I’ve made a 10′ , ellipitcal table top for a “conference room” out of coumaru (Brazilian teak), unused flooring. I need a protective finish that can easily be repaired, if scratched, etc. I plan to use Zinsser sanding sealer 1st (does that make sense?). I’m not set up to spray; & am not that great with a brush, so a wipe on would be preferable. I know I’ll need several coats.
The other thing that I’ve thought about is, since coumaru is so hard, do I really need such a hard, protective finish?
I’d appreciate input from experienced woodworkers.
Many thanks,
Morty
Replies
If left bare you would have stains and rings in short order.
Shellac, which is all that Zinsser Seal Coat is, would look quite nice on such a table. But, and it is a big but, if it will be used for office conferences the finish must resist coffee mugs or sodas. Shellac is more water resistant than some suppose, but you would still be courting major problems with just shellac. Shellac also scratches fairly easily.
I would recommend one coat of shellac, which would help tame any oils that might interfere with other finishes. Then I would use a wipe on varnish. Waterlox Original/Sealer is a very good varnish, and provides a very nice soft shine. The other Waterlox varnishes include a Gloss, which would need thinning to be a good wipe on, and Satin which takes less thinning than the gloss but still a little. Other good varnishes would include Behlen Rockhard which for wiping you would want to mix with about equal portions of thinner. Some lighter colored varnishes include Pratt & Lambert 38 and Cabot 8000 Oil Varnish.
I'm going to hijack this thread
Steve,
A while ago I switched from varnish to water based lacquer for finishing tops. Now I think I want to abandon the WB lacquer. I thought about going with a wiped on varnish, perhaps using thinned down Rock Hard, but your reference to Waterlox got me to thinking.
Would it work over oil based grain fillers?
What sheen do you think would best match the soft luster of a rubbed out shellac finish?
Can the gloss version have its sheen altered by rubbing out?
What kind of shelf life does an open can have? (Rock Hard seemed to be measured in hours, not months or years)
Thanks
Rob Millard
Waterlox is a good varnish made with phenolic resin modified tung oil, Behlen Rockhard is phenolic resin modified linseed oil. That will make them rather similar, although the Rockhard comes with a substantially higer solids content and will require quite a bit more more thinning to reach wiping consistency that the Waterlox Gloss. The Waterlox Original/Sealer is a very nice mellow shine--I guess you could call it semi-gloss--and comes at wiping consistency. I'd think it nice for Federal pieces if they weren't trying to look likely they were newly French polished, but having aged gracefully but that's a very subjective thing.
You can rub Waterlox to your desired sheen..
One thing about rubbing wipe on finishes. If you let each coat dry over night you have only a very thing film to rub without rubbing through and creating witness lines. BUT, you can apply them differently. You can do up to three coats in one day, applying the next coat just after the first has stopped being tacky--that usually means 2-3 hours apart. Then after 3 you do need to wait a full overnight period for the "set" to cure. Applied that way, each set won't have witness line problems within the set. This method allows you to complete the varnishing in about the same elapsed time as brushed on varnish. It does take about 3 coats of wiped on varnish to built equivalent film thickness as one full brushed on coat.
Yes, it will work over oil based wood fillers.
Any of the oil based varnishes will be substantially more protective than the waterborne acyrlics, largely because of better resistance to household chemicals and water.
Both Waterlox and Rockhard will have similar short life problems. Bloxygen is recommended. ,
Thank for the quick reply
Steve,
Thanks for the quick and as always informative reply. I think I will give the Waterlox a try. The stuff isn't cheap!
Rob Millard
Why the switch?
Rob,
Just curious, but can I ask why you are abandoning the water based lacquer? BTW, your blog entries on the subject convinced me to try what was then called USL and I have been pretty happy with it. I have also tried General Finishes High Performance and it seems pretty similar to the USL. Easier to apply, clean up, and rub out than the varnishes I tried although the only two I tried were Minwax and Waterlox.
Chris
Unfounded tradition
Chris,
Why am I switching? I think the phrase "stick in the mud, traditionalist" puts it best.
I too have been very happy with the USL, but I wonder how it will hold up over time. It is most likely an unfounded concern, but I know what hide glue will do in the future and shellac too. I had the same concerns about the varnish, but I wanted a tough finish on table tops. In the end what really concerns me, is the thickness of the film, not so much the product itself.
Rob Millard
Coat the underside?
Hi Steve,
Many thanks for your response to my original question, posted in May. I'm about to begin the finish using your ideas. The table top is mounted to a substrate of 3/4" plywood (with screws with some "play"), for support. Should I remove the top & coat the underside of the top with a finish, to reduce the chance of warpage? If so, does it matter what I use to seal it?
Thanks,
Morty
On a table that width, you do have potentially quite a large shrink/swell range, especially if the room where it will be housed isn't kept thoroughly climate controlled. So make sure ;your screws allow sufficient range for the width to change. (Check this calculator to see: http://www.woodbin.com/calcs/shrinkulator.htm )
So coating the underside makes sense. Ideally you would seal with the same finish schedule, but this isn't practical nor necessary given that the underside will be sheltered by plywood. However, you could use a couple of coats of shellac to do the sealling. Shellac is the best finishing material around for slowing the transfer of water vapor. It's also the fastest to use. If your shellac is fresh, coats of shellac need spacing by only a half hour or so, depending on how heavy a cut is used. .
Table finish
Will these "conferences" include alcoholic drinks? If so, I believe shellac as a finish is out; as an undercoat just fine.
I have had great luck with GENERAL Polycrylic (I've tried a dozen or so and that is why I accented the General brand. Available from Woodcraft) It is waterbased for easy clean up, dries very quickly (you can apply several coats in a day) and levels so that I have never had problems with brush marks.
I always buff up through progressive grades of Abralon pads to the desired sheen.
Frosty
Buffing Procedure
Frosty,
I too have tried and like the General polycryllic but I have yet to perfect the rubbing out process. Would you mind sharing your buffing procedure?
Chris
Buffing General Polycrylic
I generally brush on about 5 or 6 coats using a good brush. (I bought mine - the one with orange bristles - 5-6 years ago and it's still good as new. I always pre-wet the brush core so material doesn't harden on the dry bristles at the base; cleanup is easy with warm water, then a little soapy water and a rinse..)
I sand out the dust nibs after the first coat with a 360 grit Abralon pad. After that, about every other coat using my 5" ROS with a 500 grit pad.
After the finish has dried a few days, I work up through the Abralon grits: 1,000, 2,000 and 4,000. If I need more gloss I go to an automotive polish such as Meguiar's. My sanding pattern at each grit is always slowly - (a) back and forth, (b) up and down, finally (c & d) diagonally each way. The brush and Abralon pads come from Jeff Jewett's Homestead Finishes.
This process works for me. I hope it will work for you - but I expect it depends on what you expect the end result to look like. Good luck. Let me know what you think after you've tried it.
Frosty
NO! On water-based anything.. But Housepaint
As many know, I will never use water-based on anything, other than exterior/interior latex house paint.
IMHO, no way is ANY water-based so-called ' fine furniture finish' in any way equal in durability and quality to ANY solvent-based finish for table tops etc.
I would finish first with a washcoat of 1lb shellac. Followed by a brush-on coat of Deft Clear Gloss (nitrocellulose) lacquer.
I then would 'pullover' the brushed lacquer - as shown in an FWW video by Sean Clarke. (search 'pullover' and 'clarke')
Then spray (not brush) a second coat of Deft Lacquer (You can get it in spray cans). 'Pullover' per Clarke.
Spray another coat - and 'pullover' - per Clarke.
It will end up a brilliant gloss - but not look like urethane plastic. (The photo is a cherry Butler's Table finished just as described above)
Unlike any varnish, this finish is easily repairable. You simply 'pullover' it again. Yet as Steve mentioned, the varnish - either Behlens or Waterlox - is going to be more durable, if a bit more difficult to repair. Either the solvent NC Lacquer or a Varnish will be more durable than any water-based 'lacquer'.. (actually an emulsified acrylic resin - similar to latex house paint)
Also, since true solvent NC Lacquer is not cross-linked like a varnish - it reflows easily for repairs. And will look like new afterward..
Try it on scrap first , but do give it a look. Fantastic, and easy, IMHO.
The video seems not easy to find. Here is finally what I found worked:
https://finewoodworking.com/subscription/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=5213
The video shows Clarke 'pulling over' a 30" by 60" Desktop brushed NC Lacquer finish..
Chris
Hope we can agree to disagree. If the "pullover" is like regular NC, n that skin oil makes it permanently soft and sticky, it would be my last choice for a conference table or any other piece that will be in contact with skin. I grew up with NC finished kitchen cabinets and dining chairs, and after 6-8 years all had permanently dingy and sticky areas where they were handled. No cleaner would remove the dinge or the stickiness.
My opinion is that some waterborne finishes are quite suitable for residential use. But I agree with the earlier comment that in an office the cleaning staff is more likely to use harsh cleaners.
Pullover Solvent
Hi Don,
I don't believe the 'pullover' technique will make the lacquer any less hard than otherwise. The 'pullover' solvent I use is a mixture of about 1/3 lacquer thinner and 2/3 ethanol. Used with the 'rubber' pad, It will just slightly reflow the lacquer finish surface. When it evporates, the NC finish is back to its original hardness.
I don't have experience with the skin-oil softening you mention, so I would agree if that typically happens with lacquer-finished items like a conference table, its a negative.
However, if its after 6 - 8 years, I probably would still consider lacquer because its so easy to completely remove and refinish at that point.
Is it possible the skin-softened lacquer might have been a water-based 'lacquer'? I believe these are not NC lacquer at all, but an entirely different acrylic resin - and often very soft and 'sticky' to begin with.
Chris
Table top finish
Morty:
I have had very good luck with a dewaxed shellac undercoat and Behelens Rock Hard over it. You can rub out the Rock Hard to any sheen after it has cured for a couple of week os so, I actually did kitchen counter tops this way. I kind od went over the top ahd sanded back five coats of shellac, using a bit if transtint for warming, and then two coats of rock hard over that. They are now two years old and have stood up to daily use, alchohol, cleaners, and all else you would expect for kitchen counteres for a large family. No complaints excelt a couple of places where very hot items were set on them -- and that was easily repaired.
The Rock Hard has an amber cast, so you'll need to plan for that in your color schedule if it matters to you.
Joe
"rubbing out" varnish
Hi Joe,
After much aggravation (& a lot of learning), I've finally applied, what I hope is, my final coat of Waterlox Original varnish to my table top. I plan to wait several weeks, while it cures, before trying to refine the finish. I've never done this before. My hope is that proper buffing &/or rubbing out will make minor flaws (lines of thicker finish that didn't level, dust "motes", etc.) disappear. I'm interested in the process you've used to refine your varnish finishes.
Thanks for your interest & time.
Morty
finish for table top
I'm repling late to the orginal post but, why has conversion varnish not been mentioned as a final finish/topcote after staining ?
Jonathan in Colorado Springs
Because conversion varnish is pretty much a pro- only finish that requires actual spray facilities--booth, breathing protection, etc. to be used safely. In plenty of places the booth would even have to capture exhaust gases,and pretty much have to be equipped about as for spraying automobiles.
Yes, conversion varnish is pretty tough, protective stuff, but it is limiting as well. Well neigh impossible to repair for example, since for many versions no other finish will adhere, even itself after a defined window of time. It is great when you have to wrap, stack, and ship in a very short time.
Because conversion varnish is pretty much a pro- only finish that requires actual spray facilities--booth, breathing protection, etc. to be used safely. In plenty of places the booth would even have to capture exhaust gases,and pretty much have to be equipped about as for spraying automobiles.
Yes, conversion varnish is pretty tough, protective stuff, but it is limiting as well. Well neigh impossible to repair for example, since for many versions no other finish will adhere, even itself after a defined window of time. It is great when you have to wrap, stack, and ship in a very short time.
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