I’m continuing to grow in my use of shellac, but I still don’t have the technique down when brushing out large panels (16″ x 30″).
Whether I use a $30 brush or a throwaway sponge one, I am getting “window pane”-ing between each area of wet shellac when I dip my brush. You know, a thick ridge or line that shows up on edges when the finish is going down too thick, or, in my case, between each brush dip.
I am trying to brush until I run out of finish on my brush, dip and plant my freshly loaded brush about 4″ out from where I ended, and brush back to the wet edge. But, the wet edge is already setting up.
Of course, it’s really dry right now (dead of winter, central heating), but it’s almost as if the shellac is flash drying. Thinning down from 2# to 1.5# helps, but not by a lot. I just get thinner ridges.
Any suggestions would be appreciated. Of course, shellac is so forgiving that I can just sand the imperfections away, but – geez, there must be something that I’m missing.
Mike D
Replies
For me, it's the kind of brush that makes a big difference. I have a strong preference for watercolor wash brushes made with Taklon Gold fibers that are very similar to high quality sable brushes. (Art supply stores carry this sort of brush.) The bristles are very thin, and the brushes themselves have a very small "reservoir". Consequently, they don't hold a lot, and they don't leave a big "lump" when they first touch down. These brushes deposit very smooth thin coats that don't need to flow to not have brush strokes. I don't have to touch down that far ahead of the previous wet edge, and the thinness also makes it easier to not worry about having a wet edge. A overlap is so thin that they "average out" in just a few coats.
Others like large mops for applying shellac that allow spreading large amounts in a very quick fashion. These too have very thin, soft hair. I don't think I'd like this approach myself, but I've seen good results from those adept at this approach.
Of course, there is nothing wrong with padding on shellac.
I can't see using a foam brush which for me give very little control, and besides plenty of foam brushes break down in DNA. And, even very good brushes, of the sort used for varnishing, spread to much in the beginning and then taper off. For varnish this is fine, you lay on varnish and then work the brush to spread it evenly. But for shellac you don't have time to manipulate after putting it on, so it must be even from the start.
I am just a weekend warrior diy-er, but I do like shellac, and I have suffered the same problem as you, especially when finishing plywood.
For example, if my son was not such a slob, I would be able to see the top of his dresser, and that would really annoy me because of how streaky the shellac finish came out due the exact problem you described. But I digress.
The only thing that has worked for me is to use spray can shellac for the first coat or two. Subsequent coats are easier to brush on because the sprayed on shellac prevents the brushed on shellac from immediately soaking into the thirsty dry wood before you can even get to the next brush stroke.
Mike,
You might want to thin your shellac a little more, even a 1 pound cut can be too thick; shellac needs to be very thin to brush effectively. Also, add some Shellac Wet from Homestead Finishing Products. Like Steve said, the Golden Taklon brushes are great. I use a a 2 inch one for large areas. The brush should just barely touch the surface, and flow out the shellac. If you are having problems with it setting up too quickly, you can put the shellac in the refrigerator between coats, I do this in the summer, but I think thinning your shellac and adding the Shellac Wet will do more than cooling it will. If you have high speed internet, there is a short clip of brushing shellac at the link below.
Rob Millard
http://americanfederalperiod.com/woodshop.html
I got pretty much the same results with either a varnish brush or a foam pad. From the video and other inputs it seems that I need to thin the mix a little more and invest in a taklon brush, or learn to pad.
I am experimenting with padding on various shop jigs, but clearly there is a technique required with padding which must be learned by trial and error if you have no one to tutor you on it first hand.
For now, what I'm taking away is ...- thin the shellac more- use a brush with less reservoir - in other words, not a varnish brush- use a brush with softer filaments - i.e., a taklon brush- use a drying retarder
Thanks to all - the journey continues!
Mike D
The beauty of padding shellac on is that you can avoid this problem, while still finishing even large surfaces.
Be sure when brushing (or padding) that you don't press down hard with the brush, as this can lead to ridges forming at the edge of the brush (or pad). I advise using the wieght of your hand as the amount of pressure to apply.
Mike.
My solution for that problem is to really thin out the shellac.. a 1 pound cut is what I typically use but I've even used thinner.. Then I flood it on and spread it out. (I used to say I slopped it on but that's not really correct.)
I do the Indy 500 of painting when I use this technique because you have so little time to get everything covered while it's wet.. of course you will get runs, but with it thinned this much and doing things really quickly you chase those runs down and they never show.. just plan on slopping up the floor a bit..
I've sprayed shellac and there are two problems with spraying.. one if you do it in typical thin coats you wind up with a lot of orange peel so you have to really flood it on with the sprayer. (which means you chase runs with the spraygun)..
The second problem is all the prep work etc. to spraying.. It takes more time than Brushing does.. No, not the actual spraying that's a bit faster but the prep work before and clean up after.
True if I had a spray booth where I could leave everything out spraying would be faster but then cleaning the gun etc.. would still add a lot of time to the job.. My brush I just set aside let it harden and before I use it again soak it in denatured alcohol for a few minutes.. (or the shellac mix)
The advantage of this approach is that the first coat dies in 15 minutes the second coat dries in 1/2 hour and the third and final coat takes an hour to dry completely..
You do sand your first coat don't you? with 220 paper on a block or a 220 sanding sponge. Just enough to remove the nubs. real lick and promise kinda sanding about a second to a second and a half per sq.foot (more time around the edges since you need to be very carefull not to sand thru)
Hi Frenchy,
Yep, I sand with a 220 grit sponge (or 320 if that's all I can find at the moment). In fact you got me started back trying shellac, so definitely I sand after the first coat.
Actually, I have pretty good luck using your method on smaller pieces. It's the large panels that are defeating me - I definitely get 'panes' of finish, that show up on the completed piece.
I'm pretty sure that it's like any art in that it must be done over and over again until it works. Sure takes a long time to learn, though!
Varnish, I'm good at, but it does dry at glacial speed, and has to be rubbed out to remove all the dust nits, etc.
I used to hate finishing, but it's key to a good looking finished piece, so I'll just keep plugging away until I'm better at it. I surely do appreciate the shared advice that is always here on this site.
Best Regards,
Mike D
Edited 2/9/2008 12:04 pm ET by Mike_D
Mike,
If you are getting the overlap stripes then you aren't flooding it on enough. Think of dumping a pailful on only using your brush to do so.. Accept the runs and drips that result and chase them.. don't try to paint it so much as mop it..
Ever mop with a really wet mop? that's the technique. Just flood it on..
Shellac is really forgiving, just get it on and get out of it's way..
Sanding sponges are good for final finishing, but they're too flexible for leveling a finish. Use a harder block (rubber, felt or just a piece of wood with the sandpaper wrapped around it), and I'll bet you get better results.
-Steve
Steve.
I agree! I use sanding spongs only to remove nibs etc.. If I'm going to color sand (or as you say rub out) I use a sanding block. I have so many hard rubber ones that I aways grab those but lacking them I'd sure put the sand paper on a wooden block that was a neat fit to my hand..
Don't make the mistake of using a big awkward block which is hard to hold onto.. (I'm sure you don't I just am saying that for those who are following this thread)
Frenchy, I just used your method and had pretty good luck with it after some practice. Hardest part is how do you "flood" it on Vertical pieces? When I put it on vertical panels I ended up with runs and thick stuff at the botton near the rails etc. I think with some more practice I will finaly be able to finish things without ruining them.
Thanks
Dana
montec24
Depends on the size and weight of the piece. Smallish I just lay it over on it's side a bit. Nah that doesn't really describe what I do.. because it's not lain down it's simply tilted way over. If it's like a cabinet or something I start on the inside first, coating all that, flipping it as I go so I'm usually working flatish. I've got some old shelf brackets that I sharpened and screw into a heavy post to hold things in the corners slightly elevated once the inside is dry and hard. I can set it on those in the corners and hold things slightly elevated but still pretty flat.. if there are runs or drips on the outside from my flooding technique (there usually are) I wipe those off with denatured alcohol before I start on my outside. So I have a nice flat surface to work off of..
If it's really big and heavy like my piano I just set it in some drip trays and flood away. I've learned from hard experiance not to attempt to pick up a nearly full drip tray(please don't ask ;-) but use a turkey baster to return the run off back to the can..
I don't have a zillion differant sized drip trays hanging around. I make them from whatever is handy, cardboard boxes or homemade wooden ones lined with plastic.
I once made a nice drip tray out of my wifes aluminum foil but paid the price for that when thanksgiving came and she reached for the roll of aluminum foil..
Do you know how hard it is to buy a roll of aluminum foil on thanksgiving? I spent hours trying and came home all hang dogged, meanwhile she-who-must-be-obeyed had gone over to the neighbors and borrowed some..
Hah! The weather forecast today said "colder with wind gusts to 45 mph", so naturally, as I was applying coat #3 of the Pratt & Lambert #38 I had the basement window open (with a fan blowing out) to carry away the fumes. These panels were looking NICE.
JUST as I finished, one of those 45 mph gusts blew my fan in, along with a nice cloud of dirt. Oh! Gosh! Darn!
So, in 24 hours or so, out comes the orbital sander, Abranet, and vacuum attachment, and off comes that layer.
Sigh.
Mike D
Thanks for the advice Frenchy, I think once I get the hang of this I can use schellac and finally be happy with the finish I apply!
"She-Who-must-be-obeyed" Haven't laughed that hard in a while, thanks for the laugh
Dana
I get some shellac 'corning' on sandpaper when using a hard block, even when I've let the coat dry overnight,
But something that I discovered this morning was that a 220 Abranet sheet on an orbital sander, held VERY lightly, with a hard Abranet adapter (for airflow) attached to a shop vac, cleans up the surface quickly and cleanly, but not over-aggressively. And, is seemingly not susceptible to 'corning' on the surface of the abrasive, at all.
Very fast, very flat, and doesn't take all the shellac off if you use a very light hand and don't linger.
Mike D
P.S. I'm following up a shellac seal coat on a cabinet that I'm making with Pratt & Lambert #38 for the top coat. This is an non-poly oil varnish - soy based - recommended by a kind finisher, and really nice looking going down over the shellac base. I really like this varnish from what I am seeing initially.
However, the can specifically states "Do Not Thin". I've put down a coat un-thinned, and a coat on another piece thinned about 10% with odorless mineral spirits to compare, since most oil-based finishes seem to do much better when thinned a bit. I've gotten better flow-out with the slightly thinned mix, but it's more prone to air bubbles off the brush when thinned.
My plan is to lightly sand between three coats of the #38 to remove dust nibs, etc, and then wait 3 weeks before rubbing the final coat down with 0000 steel wool and Johnson's paste wax. This piece will see a lot of use, so I'm hoping that three coats over the shellac will suffice.
Edited 2/9/2008 5:19 pm ET by Mike_D
Edited 2/9/2008 5:23 pm ET by Mike_D
Mike,
All oil-based finishes say "Do Not Thin" now. They have to do that so that they can meet VOC laws. In the real world you can thin it as much as you want. Hell, I thin a little extra just to stick a finger in their eye.
Three coats of #38 thinned 10%-15% should be just fine. If you want to you could go 4 coats, it won't hurt anything.
As far as the look goes, yeah, I love the look of a soya based alkyd resin varnish. I use McCloskey Heirloom myself, but they are about the same thing. Of course now that Cabot is folding all of the McCloskey products into their line I won't be able to get anymore when my supply runs out. Supposedly Cabot oil varnish is the same thing, I don't know for sure though.
Rob
Hi Rob,
Yes, I think that thinning is probably a must. I just put on coat #2 without thinning since it flows on so well, and darn! when I got through, I found two small holidays. I'll touch those up tomorrow morning with a small brush. Wouldn't have happened if I'd thinned, since the thinned coat wets much better.
Have you ever used Penetrol on varnish to improve the brushing out characteristics - actually the leveling characteristics? I love the stuff with enamel, but nothing on the can of Penetrol suggests that it might be compatible with varnish.
Mike D
Mike,
I've never used the product, but reading the MSDS sheet shows it to be 58% - 68% stoddard solvent. Stoddard solvent is just a fancy name for mineral spirits. Since most oil base paints are basically a varnish with pigments I would think that if you feel that thinning with Penetrol gives you a better result than thinning with mineral spirits you could use it. Mix a small test batch of varnish and penetrol and compare it to varnish and MS and see if it is worth the price difference.
Rob
You mean (gasp) do a controlled test? Hummmmmm, you may have something there. :)
Good idea! I'll report back in a couple of days.
Mike D
Mike:
Get some isopropyl alcohol (pure, from the hardware store, not the 30% stuff from the supermarket).
If you're buying 2# cut premixed, mix the isopropyl alcohol (iPA) 1:1 with denatured alcohol, and use that to solution to dilute down to a 1# - 1.5# cut.
If you're making your own shellac solution from flakes, use 10% iPA and 90% denatured alcohol for dissolving.
The iPA will slow down the evaporation rate, and allow the finish to flow out further. Of course, it will take longer to dry out between coats.
-t
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