Okay, here’s the deal. Am hoping someone out there has encountered this and has a resolution.
I’ve been working a job for the clients while they’re gone to Europe for three weeks. Job scope is to recolor and refinish all the woodwork in the house. Most original jambs, crowns and casework is poplar. Ugh. I’m sure it was installed with the intention to paint it, but it was eventually stained instead and finished. You guessed it. Blotchy. My job make it look great. No problemo.
We’ve spent many hours cleaning it (tsp) and wipe down with naptha. Mask off everything except the wood. Two coats of Sealcoat and allow to dry. Several dry mist coats nd then a full flow-out coat. No signs of silicone present on the surface anywhere when done. Coloring via Mohawk base concentrate in nitro followed by several nitro topcoats. Shooting HVLP. Temps have been great and low humidity to boot. Excellent results. Only a very well trained eye would be able to detect that it’s not walnut.
Now we’re down in the dining room; the last to do. Disaster has struck. There’s two windows in there; a large bay with window seat and “the other”, a conventional casement with conventional sill. All interior window wood in the house is maple including these windows.
Colored and shot these windows two days ago and went home around 8:30. Everything is fine. Return the following morning to find gobs of frosted little domes on the one sill. Ugh. I grab the gun and mist some lacquer thinner on the stuff to hopefully release the apparent moisture. I soon discover that the new can of lacquer thinner I used to reduce that particular batch of lacquer has water in it. Grrrrrrrrrrrrr. Somebody probably refilled a partial can and returned it for a refund. Cost me the rest of the day stripping the window to start over. The finish in these bubbles had released all the way to the Sealcoat, taking the color coats with them.
Left last night after a redo. Everything is fine. Return today and there it is again only this time without the frosting from moisture. Gobs of little domes on the sill again that look like they’ve been inflated with a compressor from underneath. This ain’t fish-eye, they’re bubbles. Again all the way to the Sealcoat, which was refreshed after the strip job. All these bubbles are in the exact same locations again on just one half of that sill, but none of them touch each other. There is space in between.
No signs of moisture in the sill either. Bone dry.
Replacement is not desirable in this instance, if it can be avoided.
I’ve been in the biz since 1972 and have never seen this before. (And yes, I know that nitro isn’t necessarily the best choice for windowsills in most households, but these folks never open the windows and the house is heavily shaded all day. We still have all the other window sillsand jambs to go later this summer/fall and those will receive varnish.)
Clients are due home on Tuesday morning. Ugh………..again.
Anybody?
Knowledge is power, but only if applied in a timely fashion.
Edited 8/3/2003 5:12:13 PM ET by GOLDHILLER
Replies
If you hadn't said bubbles are reappearing in the same exact same spots, I would say the cause was sunshine---I had a very similiar problem--sprayed a table top and before the material was totally dry/cured, the sun came around and shone on the top thru an open garage door---the additional heat caused the solvent in the fiish to evaporate and caused the bubbles---since your project was in a window---could the sun have come around and caused part of your problem??? I also had to redo the top, all efforts to salvage the finish at that point were a waste of time......
Thanks for the response, George.
Nope. Sunshine wasn't the problem. I know what you're describing as I suffered that sort of thing once in my infancy of finishing. It's been extremely pleasant here, but partially overcast for days and this window faces east. Trees right there to shade it too.
The bubbles are in 2 stripes down the sill about 1 - 1 1/2" wide, maybe respectively 8" and 10" long. Baffling to me. Something it would seem has contaminated the wood in this sill and is able to leach up thru the Sealcoat without causing its bond to fail. Blows bubbles in the process. Colored bubbles in this instance.
Unless I get some brainstorm here, the dream of having it all done, neat and tidy when they return is shot. I'm pretty much resigned on this Sunday aft. to leaving it alone so that they can see for themselves. Maybe stuck with replacement yet or maybe a dutchman if acceptable to the client.
Sill edge profile is such that it would may require a custom knife to reproduce. Haven't taken a profile of it to compare to my array of cutters and bits.
I'm sure they'd approve of my use of their computer here if they knew what it was for. :-)
Knowledge is power, but only if applied in a timely fashion.
It's hard to say without being able to look at it... but, it sounds like solvent pop. It sounds to me like there are solvents trapped underneath the topcoat which are causing the bubbling as it tries to escape.
I would redo up to the color coats, allowing sufficient time for each coat to flash properly and then give it an overnight dry before topcoating. On the top coat I would slightly over-reduce a batch of nitro with a 50/50mixture of PM Acetate and MEK and put on a thin layer, let it dry for 30 minutes minimum and continue on this way until you're happy with the appearance. The MEK will flash quickly and not cause problems, while the PM Acetate will flash very slowly and allow any trapped solvents to escape. I'd probably also put on lighter coats of the SealCoat too, just to ensure that the solvents are all flashing out properly.
Why you're having problems with the Maple and not with the Poplar, I don't know. But, it sure sounds like solvent pop to me.
Regards,
Kevin
Thanks for the reply.
Perhaps that may be it. Seems odd it would occur in exactly the same places every time tho. Huh.
May be worth a try.
I think at this point I'm going to put my panic aside and just let the clients see this problem. Then they can make the call as to try again or...do one of the alternatives. That way they'll also understand the extra billing involved. This whole deal is, of course, cost+.
Mightily expensive too, but still cheaper and preferable to replacement or removal/reinstall. Mucho expensive faux paint jobs, high priced wall papers and custom artsy plaster jobs at stake.
Edit: Just remembered that the first time this problem appeared (bubbles), the color layers were applied approx. 10 hours prior to any topcoat. And that on the second attempt, the areas of the sill that received the most shading and consequently the most material (around the base of jamb) weren't bubbled at all on either side.
BUT.................I just realized that it is this window thru which we are venting the room!!! Duh. I've got a blower set up to circulate out this open window. Maybe the top of the material is skinning over to rapidly in this striped areas and it is solvent pop. Yeah. Could be, I guess.
Should I risk one more encounter with the sill of doom?
Edit again: Naw that ain't it. The blower has been sitting there whisking air past wood much, much closer than that window sill and zero problems anywhere else.
Almost has to be a contaminant....I think. But then there is the bubble blowing to explain. I dunno. I'll keep thinkin' and hope others do, too.
Knowledge is power, but only if applied in a timely fashion.
Edited 8/3/2003 5:48:03 PM ET by GOLDHILLER
Edited 8/3/2003 5:54:41 PM ET by GOLDHILLER
I had considered the possibility that the color coats were the culprit too. I know that is a standard explanation for solvent pop because a lot of pigments used in color coats have very slow solvents associated with their packaging. But, in my own experience that has never been the culprit of solvent pop. What I've seen cause solvent pop is the solvents associated with lacquer, whether it be a direct cause from the lacquer or the solvents getting trapped in some type of contaminent underneath.
It does seem odd that you would get the bubbling in the exact same place unless there is some sort of a contaminent there which is trapping the solvents. Are there any hairline cracks in the Maple underneath those areas? Anything at all that would allow solvents to seep in rather than flashing off like they are supposed to?
I dunno... it's odd, I agree. And from your description of your process it certainly sounds to me like you've taken a very informed, conservative approach... which is virtually always the best way to go. Clearly you know what you're doing as a finisher. Still... I don't know what else could cause the bubbles that matches your description other than solvent pop.
Was the existing finish ever waxed?
Regards,
Kevin
Well..........from the get-go (and before) of this project, I was concerned and convinced that the woodwork in this home had been slathered with Pledge over the years and proceeded accordingly. The bottle of Sil-flo remains yet in the door of my truck. I'm really not anxious at all to use it in this particular gun for fear of contamination. Then it's Sil-Flo for life somtimes.
The original and only finish most of this woodwork had ever seen was shellac. I seriously doubt that anyone here over the years was ambitious enough to wax the window sills. :-)
Hairlines? Can't say with dead certainity. but what i really came up here again to do was report what I was remiss about earlier. when I first approached this sill with the Sealcoat, I took to shooting a full wet coat. Whoa!!! There it was. Our nemesis....MR. Sili rearing his ugly head. I grabbed some alcohol (no, not for me) and wiped the sill down. Then started the dry coats. About 8 altogether I'd say. Let em dry well. Threw down a full wet coat. No evidence of problem.
BUT....(I'm good with throwing that in all the time, huh?) it occurs to me now that these bubbles are appearing right where that silicone was and yet how could that make it's appearance now and why would it blow bubbles?
You're pretty good at this Kevin. Keep thinkin'..keep thinkin'. :-) We just might lick this yet.
I'm thinking about going at this in a week or so after the folks have recovered from their trip and REALLY laying on the Sealcoat over a period of days. Same with the color and the clear coats. Whadda think?
Anybody else gonna take a crack at the hall of fame? <G> There is an answer somewhere.
Knowledge is power, but only if applied in a timely fashion.
Has the bad area been striped down to bare wood? Maybe some tape had been on the wood in the past and has contaminated the wood and thats what left over glue keeps being "pulled" to the surface. (just guessing, as you seem to have tried many other things)
Yes sir, it's been down to bare wood twice now.
The part of this story I left out is that both the bay window seat and this casement sill were the vicitms of two anxious doggies awaiting their owners return from work.
We've worked extensively in, on and around this home for the last five years. It has provided us both with approx. 80% of our work in that time. We're "staff" so to speak. <g> Been meaning to talk to them about a 401 when they get back. Anyway, I know the routine. Every time the dogs heard a car coming down the street, they rushed to the windows, barking and a lookin'. Deep nail scratches galore on these two windows.
To remedy the problem, months prior to this renewal process we tagged into the invisible fence unit and ran a wire under the dining room and living room floor. What a shock (pun intended) to both dogs when they next ran into the room. Yarp, yarp, yarp. Yep, they're trained now and never enter these rooms.
And so, I sanded the sills well prior to the initial coatings and sanded again after the first failure.
It was a viable notion for the source of the problem, but in this case I don't think that's it. I have wondered just what might have been poured/spilled onto this sill in the past and allowed to soak in the virtually finishless surface tho.
Would doggie drool do this dastardly thing? Maybe I should talk to a vet. :-)
Knowledge is power, but only if applied in a timely fashion.
I know my dog would do the same thing to the window sills. I had to use some wood filler (really I use car body filler) maybe a reaction to this?
I had to use some wood filler (really I use car body filler)
::: Kevin's off on a tangent again... :::
Years ago I was the finisher on a job involving the upscale lobby of a local beer and wine distributors brand new building. Everything was solid and veneer cherry with a medium dark cherry stain. The sides of the solid Cherry stairway caps blew out really bad when we were milling them. Not wanting to have to buy that much more wood the shop foreman decided to try autobody filler with the red cream hardener on the hopes that I could stain it so that it would blend in since it would be red anyway. Amazingly enough, you couldn't tell that the filler was even there when I was done. And all I did was mist a bit more stain on the sides to darken and muddy it enough to obscure the difference between the wood and the filler. Nobody but us ever knew the difference. It looked great when it was installed.
Regards,
Kevin
It's a thought, but no. No fillers ever used on this sill......or anywhere else for that matter.
The whole deal is kinda hard to understand. I can't really understand why this house ever had poplar woodwork installed as it's one big fancy elaborate residence. I'd trade in a heartbeat if I could afford the taxes. Anyway, the only apparent finish ever applied was a couple coats of shellac which have grown thinner and thinner over the years. And until these folks bought the place and began renovations, it seems that no one did anything to maintain the cosmetics................except squirt a bunch of Pledge around when company was coming over.............or maybe our favorite......Liquid Gold. <g>
Maybe I should be grateful because for that reason we don't have to fight all manner of numerous coatings, paint and ill-conceived repairs. So far this one sill has been the only fly in the recoloring/refinishing ointment so far. The rest of it all has come out to my fondest dreams and hopes without problems. I know what wood is really under there and even my mind says "that's some really nice walnut" every day when I walk back in to continue. My job however was made easier because they at least used some nice poplar.
Knowledge is power, but only if applied in a timely fashion.
Well... all the nitro lacquers I've ever seen (as well as lacquer thinners) have some alcohol in the mix. So... it may be that, because of the alcohols, the lacquer coat is softening up or maybe even penetrating the Sealcoat and nullifying it's value as a barrier coat.
What I would do is take the same approach with the nitro that you did with the Sealcoat. If the surrounding areas are all dry, I would mask them off... omit the PM Acetate idea and just over reduce slightly with MEK, since it will flash very quickly and that should prevent the lacquer from biting too deeply into the Sealcoat. Go with multiple light coats just like you did with the Sealcoat and that should work. I'm a huge fan of using MEK with nitro lacquer! The MEK acts so strongly to reduce the viscosity of the nitro that it works almost as well as a retarder in nullifying any overspray/orange peel issues. There should be enough slow solvents already in the unreduced nitro to prevent any blushing problems as long as you only slightly over-reduce with MEK (20 - 25% max). Of course putting on light coats will in itself help prevent blushing.
Whether the actual culprit is silicone or something else is almost immaterial. As you already know, light coats almost always work beautifully to enable you to bridge over any potential contaminents. The same approach should work just as well for the lacquer coats as it did for the Sealcoat coats.
Regards,
Kevin
Edited 8/3/2003 7:50:28 PM ET by Kevin
On your recommendation, I think I'll try what you suggest. After all, it can't be any less reliable than what I've done already and may just turn the trick.
I agree that at this point, the source of said contamination seems moot. The task at hand is to overcome it by whatever means will work…….and I'm fast running out of options to try, short of dutchmen or total replacement. Veneer on a window sill doesn't seem like a good notion at all.
It occurred to me however that one other potential option is still awaiting trial and error. I could switch to Mohawk universal colorant and select a varnish to use right away. Since I intend to use it on the other windows in the house eventually, I might just as well purchase now and have a shot with that. No lacquer thinners involved.
The problem with this is that a minimum order is $85 right now and by the time the shipping and handling is tagged on, I'm in for about $106 to lay my hands on one can of the stuff. Ugh. What other colors shall I order to fill out the $85. Decisions, decisions.
In case you're wondering why I chose nitro to use on the woodwork in this house rather than maybe a cat-lacquer, like Magna-Max..........ease of future repair is the reason.
TO ALL…………..It's all a bit of a quandary yet, but I do want to wholeheartedly thank all of you who have responded so far. I owe you all a couple of brews.
Knowledge is power, but only if applied in a timely fashion.
I absolutely agree about the ease of repair with nitro. I love how you can scrap and sand down a run in nitro lacquer, mist it with MEK and a splash of retarder and it reflows into a perfect finish without having to be resprayed.
Have you ever tried precatalyzed nitro lacquer? It's a happy medium between post-cat lacquer, like Magna-Max and regular nitro lacquer. And it repairs almost as easily as regular nitro. I use Sherwin Williams precat at work and I like it a lot. I think M.L. Campbell calls their's Magna-Lac. It's good stuff too. But, I can buy the S-W precat for less $$$.
I've been using the S-W precat for a couple years now. But, the design firm on a current job called out catalyzed vinyl on the spec sheet for this one visitor's center job up in Alaska. I'm using S-W's Super KemVar "M" for the job and I gotta say that I am deeply impressed. I'm seriously considering switching to this stuff as my stock finish of choice. It's not gonna repair any easier than any other conversion varnish. But, man.... it sprays out to one fine finish. It is silky smooth to the touch. LOL it's hard to keep my hands off of the finished goods. It's also harder and exceptionally resistant to chemicals.
Regards,
Kevin
You are indeed experienced with finishing.
I haven't tried the KemVar "M", but I will say that I'm not a big fan of Magna-Lac personally. Used alot of the stuff over the years, but the problem for me comes at rubout time. My excperience is that it leaves scratches larger than the abrasive being used. Always hated that. Magna-Max on the other hand, always rubs out for me like nitro.
Maybe I should give the Kem-Var a try. Sounds like it might be a nice product. How's the rubout on that in your experience?
I must say at his point that the allure of cat-finishes is waning with me to some degree as I get involved in more and more restoration work. They have their place to be sure, but I think we can draw a comparison to adhesives...........hide glue, for instance, is reliable for most/many normal circumstances and allows for ease of repair. It seems the need/desire for lower cost and immediate speed dictates alot of choices being made these days. Gotta admit that I do that myself.
But since I'm more and more "the next guy", I appreciate the ease of repair as do my clients. Much less taxing on the wallet. Stuff that's costly to repair is frequently tossed aside in the landfill and the new is brought in to replace it. Seems sad to toss history in the dump with reckless abandon to save a few bucks.
Consequently, I "council" my clients these days about their immediate desires for cheap cost and maximum durability when at some point their concerns may well be about the ease and cost of repair.
Knowledge is power, but only if applied in a timely fashion.
I never rub out my finishes. So, I can't address that aspect. I always select a stock sheen or adjust the sheen myself with flatting agent. In the business that I'm in (tradeshow, interpretive, and museum exhibits, with some upscale fixturing on the side) there simply isn't time or money for hand-rubbed finishes. As long as I can continue to get finishes that range anywhere from a 5% sheen to 85+% sheen range without sacrificing anything in terms of the film's properties, I'll continue doing things this way simply because it improves the bottom line for my employer. I'm fortunate in that I use a lot of Sherwin-Williams finishing products and it just happens that one of their main finish materials labs is located right here in Portland. So, I'm always able to get on the phone and talk with the labs guys if I ever have a question about film properties, reduction approaches, whatever.
I definitely hear you with regard to the advantages of nitro over the catalyzed stuff. It seems to me that shellac is getting more popular in large part due to many of the same reasons why you prefer nitro over conversion varnishes. That's also the one reason why I'm still hesitating to switch to the Super KemVar as my stock finish option.
BTW have you thought about maybe using shellac on that problem sill?
Regards,
Kevin
I don't mean to sound like I'm totally down on cat-finishes. As you're well aware, there's kind of a sliding scale in furniture finishes; durability on one end versus ease of repair on the other. It's always a trade-off whatever finish we choose to use on any particular project/product, but one must be chosen and used nonetheless.
Do I still use cat-finishes? You bet. They have their place and do offer notable durability with relative ease and speed of application. But I guess I'm more critical of my decision concerning the advisability to use them than I use to be.
Shellac as the final finish? I'm too stubborn to give in to that yet. That may be a consideration if this next attempt fails, but for now I'm diggin' in my heels. :-)
Knowledge is power, but only if applied in a timely fashion.
Well, it's time to once again return to my little dilemma described above in this thread.
Here's the latest.
Clients return from trip and are VERY pleased with the results.....except of course for that one window sill with the problems. I'd sent a little note along with the folks that picked them up at the airport so they'd be prepared and knowledgable when they once again entered their domain. Not a problem to them as they know I'll get the thing done right eventually even if replacement is required.
So this morning I am summoned by them to come and resolve a totally different problem. Computer problem to be exact. Several problems to be really exact. About half an hour after I arrive I wander into the dining room to have a look at the problem sill again. Eeeeeeeekk!!! What the H is that? There on the window seat, which was just fine, there is now a blistered/bubbled area about three inches in dia. right about dead center of the seat. These blisters average say 1/8" dia. and there are approx. 20 of them in the 3" affected circle. I asked when that had shown up and was informed that it just appeared this morning. They said it was fine last night yet when they went to bed.
Today is 6 days since that seat was shot with it's final coat. No visible problems until this morning. I am now faced with stripping this window seat also and having another go at it as well.
Of course, I still don't know what the source of the problem is, but I'm now considering perhaps a coat of West Systems epoxy as a barrier coat or switching over to varnish on top of Sealcoat and abandoning the nitro altogether on these two areas.
(Computer problems are resolved. No blisters there.)
Any and all comments and suggestions are desperately welcomed.
Knowledge is power, but only if applied in a timely fashion.
Wow! That definitely isn't classic solvent pop. Something has got to be gassing off under there. But... 6 days later??? Very, very odd indeed. I've heard of solvent trapped underneath a finish for that long or longer. But, the end result is usually delamination of the topcoat or degrading/chalking of the topcoat. This bubbles after six days thing is a new one to me. Are the bubbles still translucent?
The fact that it's all in a confined area sure argues for it being a contaminent of some sort. Especially this seat with the small circled area. Three inches sounds like about the diameter of a small can. Maybe too big a circle for a can of Pledge?
Can you see the bottom of the seat? Or is it built in place so that the bottom of those boards isn't viewable? I'm curious as to whether there is any type of staining that you might be able to see on the underside of that same problem area.
Well... I'm just sorta rambling here as I think out loud... Is the lacquer right around the bubbling soft at all?
Y'know... I'm wondering how fast the epoxy kicks off. If it doesn't kick off completely relatively quickly then it might not help. Didn't the sill bubble the same day? Or was it the next day that it bubbled?
That's probably enough rambling for now. I'll keep pondering this dilema.
Regards,
Kevin
Thanks, Kevin. I figured you'd grab hold of this again.
Bubbles/blisters are colored as before. And yes, they are softish in nature. Again they have occurred between the Sealcoat and the lacquer. Sealcoat is still fixed to surface. On top of that is the colored lacquer and then the clear coats. Damndest thing ain't it? Been at this for quite a while now and I've never seen this before.
Zero problems on anything else in the house; jambs, casings, base and crowns. Now they want me to do the open staircase and balastrade. No surprise there really. The rest of it is really nice to look at.
Window seat is built in place. No access to bottom without destruction. Not at all desirable if I can get it done without.
And yes, the casement sill bubbled sometime between my departure and return in a 10 -12 hour period.
At least they aren't bent over it. They have faith that I'll get it done.
Now if i can only figure out how to do that walk on water thing. <g>
Knowledge is power, but only if applied in a timely fashion.
Edited 8/9/2003 12:35:20 AM ET by GOLDHILLER
Edited 8/9/2003 12:36:35 AM ET by GOLDHILLER
The Mohawk base concentrate in MagnaMax? Not my favorite choice for this application because of the proclivity of cat-finishes to scratching, but......... Or maybe some Mohawk universal colorant in that KemVar you like so well?
(either on top of renewed Sealcoat, of course)
Knowledge is power, but only if applied in a timely fashion.
Well... here's what I'm thinking: Whatever is causing the problem is going right thru the shellac SealCoat without damaging it. And didn't you say that the original finish was shellac? So, whatever this stuff is that's gassing off under there apparently got there by penetrating the original shellac and is escaping thru your SealCoat the same way. I'm not up enough on organic chemistry to narrow down the possible culprits. But, it seems to me that even though it's not a real durable finish... redoing the problem areas using shellac as your topcoat might be the way to go. At least with shellac you know that whatever is down there isn't going to bubble. Right? Plus it's easy to repair when it gets scratchs and it also tints the same way nitro does with dyes.
I will hazard a guess as to what might be causing the problems, after all. We know from the fact that shellac can be purchased "dewaxed" that at least some types of wax don't cause problems with shellac like they would with lacquer. That is probably in large part due to shellac only being reduced with alcohol. Anyway... one of the things that Naptha (which you used to wipe down all the case work and stuff with, as you mentioned in your first post) is used for is as a wax and grease remover in body shops. The Naptha dissolves wax very readily. Now... you've speculated about how Pledge or something like it probably had been used for years in that house on the finished goods. If that's the case then the Naptha that you wiped the stuff down with probably softened up whatever waxy residue was inside the wood or on the bottom side of the wood if there had been an old spill there... In fact an old spill would make more sense and would explain why you're not having these bubbles all over the place. Something waxy had to have been spilled on the seat and the sill at some point (assuming my hypothesis here is correct, of course). So anyway... wax that's dissolved by/in Naptha doesn't dry very fast at all. Naptha is a common ingredient in lacquer thinners and I believe it is used in lacquer to control one of the non-nitro resins/plasticizer... I'm not totally positive about that. I'd need to refer to my books at work, which I won't see again until Monday. To cut to the chase here... if there's Naptha that's slowly gassing out of a waxy concentration in your seat and on the sill, then it's gonna prevent the lacquer from curing out all the way... leaving it soft enough to still bubble after 6 days of dry time.
If my little hypothesis here is correct... then you can either strip off the finish in those two areas and plan on waiting for a week or two just to make sure that it's all gassed out... Which isn't a bad idea really. Or you will have do some phone work and find out if Naptha slowly gassing off is going to pose a problem for whatever alternate finish you choose to use. Except for shellac which apparently isn't fazed by Naptha.
What do you think?
Regards,
Kevin
Edited 8/9/2003 1:26:59 AM ET by Kevin
Edited 8/9/2003 1:35:41 AM ET by Kevin
What a saga. I think Kevin may have something. If you just need a little push here it is . Use the shellac man for god sake use the shellac .Keeping the build up of finishes homogenous just makes sense.some counseling may be inorder. Once a laquer head always a laquer head. Shellac tho not as durable is a freindly finish to repair and it smells so much better. I' ve learned quite a bit from this little discussion.Keep us posted on this dilema.
Once a lacquer-head, always a lacquer-head. LOL
And I do know what you mean cause I know guys like this, but I don't resemble that remark. I'm the one frequently preaching to them about how the use of it is inappropriate so frequently. Bathroom vanities or kitchen cabs in nitro? I.... don't... think...... so. And you've read my thoughts on the undisciplined use of cat finishes.....including cat lacquers.
Fact is I turned away from nitro on most everything except stringed instruments many years ago because of the lack of durability and resistance........and only recently returned to it. I've shot many gallons of everything from cats to polys to marine varnishes. Now how many guys do you know these days who do this for a living that'll put up with the slow dry of oil-based poly and then wait a week or more for a rubout? I do. No 12 step program needed here. <G>
Yes, I've extolled its virtues here recently over the use of cat finishes as a panacea, but I really have used it with over the years with judgment and restraint. Primarily because I'm old enought ot have seen gobs of furntiture come thru our shop for damaged finishes when it was the finish of choice of virtually all furniture manufacturers.
Iffin ya was to come to my house and see the pieces here and those at my clients homes, you'd be retractin' that there remark, by cracky!
Seriously tho, what you're sayin' about me giving up the obstinance of using the nitro or anything else on the sills makes perfect sense. If we already know the shellac wants to stay in place.......well, use it. Now if I can get it colored with the same material and get the sheen in aligment with the rest........I just might do that.
Thanks for the input.
Knowledge is power, but only if applied in a timely fashion.
WOW. You've spent alot of time just getting that all in text, let alone the thinkin' time. Very much appreciated, well thought out and makes good deductive sense. And I've been the same places with it im head as well.
Only one problem with the notion that it's from the naptha........The window seat and the sill never saw any naptha. Those are the only places in the house that are blistering. OUCH!!! Sorry.
Everything that was naptha-ed is fine.
The window seat was stripped because there was enough finish left on it between the dog nail scratches that I didn't want to clog that much paper. And then that window seat was sanded.
The casement sill never saw any naptha because I just set the sandpaper directly down on the thing and away we go.
And I don't think that applying naptha to those sills is going to resolve the problem. Might. But they've both been throughly cleaned and sanded.......at least once. And enough wood was removed to eliminate all those deep nail marks.
Yup. There's something under there that wants out all the time.
I still owe all you folks a few cold brews. Hmmmmmmmmmm. Now maybe that's a thought. If I was to strip these back to bare wood and then spill beer on them..........and let it set all night.......
Knowledge is power, but only if applied in a timely fashion.
LOL well... that's why I called it a hypothesis instead of a theory. Of course it could still be Naptha or one of it's family of solvents that's in the lacquer and is penetrating thru the SealCoat. But... it's academic now. What caused the problem bugs the heck outta me because it remains an unknown. (I have this love/hate relationship with mysteries that's the main thing keeping me engaged on this particular mystery.) That's something that can be pondered over mulled wine thru the cold winter months, though. Your more immediate concern is, understandably, figuring out what to finish those areas with that won't bubble.
I still think that shellac's the way to go. I'm actually not a big fan of shellac except as a stain-blocking primer coat under latex. I prefer thinned vinyl sealer as a transparent barrier coat, personally. But... shellac seems to be the only type of finish that we know for sure isn't affected by whatever is gassing off under there. So, it gets my vote.
Editor's note: Y'know... just for the sake of argument here, the catalyzed vinyl might very well work too. Once it's cured out it's not fazed by much of anything. AWI (architectural woodworking institute) strongly recommends cat. vinyl as the finish of choice for woodwork going into laboritories because of it's exceptional chemical resistance. But, without knowing for certain what is gassing off under there... it's hard to say whether the cat. vinyl would cure out properly. It probably would IMO. But... it'd be a gamble that I probably wouldn't take at this point if it were me who would have to restrip the finish if it bubbled again. LOL
Regards,
Kevin
Edited 8/9/2003 1:53:09 PM ET by Kevin
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