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Hi there,

After watching a video by Paul Sellers on brushing a pre-mixed shellac finish I thought I would have a go myself.
I picked up a small bottle of shellac sanding sealer (by and brand called Barrettine) and followed Paul's instructions as close as I could. I shook the bottle to mix it, poured a small amount out and began to brush the shellac onto a sanded piece of scrap beech.

The finish seemed to go on fairly thick and wouldn't brush out no matter how quick I was - I'm aware it dries very quickly - and there were tons of air bubbles in the finish as well. I tried three coats, leaving 30 minutes between each one and each of the coats looked very dull and almost cloudy on the surface. After using #0000 steel wool and a clear paste wax it was every so slightly better, but that's probably just from the wax itself! No gloss whatsoever, which I was very disappointed in.

What could be wrong here? My first thought is that it is just a cheap bottle of shellac and that I should get some of the liberon stuff Mr. Sellers used. What about the air bubbles that were introduced? The bottle clearly says to shake to mix but should I try stirring instead?

Many thanks for any help!
 

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Are you in the UK? Never heard of Barretine. Anyway, it sounds like the shellac needs to be thinned. Solids content of shellac is typically referred to as "the lb cut", which means the number of lbs of dry shellac dissolved in 1 gallon of thinner. I usually brush with a 1 to 1-1/2 lb cut, which is very thin. Find out what "cut" the shellac is you purchased, then thin it using denatured or ethel alcohol. Chances are the dull, cloudy look is a combination of brush strokes and possibly blushing. If the humidity was high, moisture can get rapped in the shellac and cause a cloudy look. Usually this will disperse in a few hour to a few days depending on environmental conditions.
 

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It could be the Brand of shellac your useing that gives it the Dull finish but I always Stir shellac as shakeing it is what causes the bubbles to form. I use Zinsser Bulls Eye Clear Shellac and have no issues with it coming out dull an then a rub down with #0000 steel wool brings up an even better shine. If it is a little to thick just thin it with Denatured Alcohol.
 

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Discussion Starter · #4 ·
I am in the UK yes, but I've never heard of Barrettine either!

There isn't a cut number listed on the bottle, but it does say "final coat can be applied using a 50/50 mix of sanding sealer and Methylated Spirits" (denatured alcohol in the US). Is this a sign that it could be quite a thick cut?
 

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For premixed shellac I have used products by Zinsser. One is with wax and one is dewaxed. Both have been very thin and very shiny. The de waxed version is called seal coat and doesn't really say shellac on it.
 

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I am not sure but I think the Zinsser Bulls Eye Clear Shellac is a 2 Lb. cut from the can (even thou it does not say on the can) and I usually cut it 50/50 from the can. If your going to use another finish on top of the shellac most people advise useing the Dewaxed to prevent issues with the other finish not sticking to it , but I have done it with Waxed and not had any issues but that was only because that was all I had at the time. But I prefer to use the Dewaxed just to be safe if I am going to put Poly or something eles on top of it.
 

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Did a quick search on Barrettine shellac. Could not find the "cut", and nothing about waxed or dewaxed. From the pictures it is definitely waxed shellac. As others said it is strongly recommended not to use dewaxed shellac under other finishes - the wax inhibits mechanical bonding. The dewaxed shellac by Zinsser in the US is a 3 lb cut, and it's possible the Barrettine is the same. Try thinning it 1 oz product to 1 oz DNA which will provide a 1-1/2 lb cut. It can be thinned as much as you want.

Not sure about the European versions but the pre-dissolved Zinsser in the US has chemicals added to extend shelf life. These chemicals can sometimes not interact well with topcoats, mainly waterbased finishes (I have experienced this myself). No such problems with solvent poly or lacquer. Due to this I use dry shellac and mix it as needed, marking the date on the container. Typically shellac is good for ~6-12 months after dissolving. If you are wanting to topcoat the shellac and can't find dewaxed, you can let the shellac sit and the majority of the wax will settle to the bottom. You can then pour the clear dewaxed shellac off the top. There is a lot of info on the web about shellac for finishing. Here is one.
 

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First, clear off the paste wax with mineral spirits.

Shellac is easy to fix. Get a piece of cotton fabric and put some gauze, cheesecloth, or wool pad in the center. Add some denatured alcohol to it until it is just very slightly damp. put a few drops of oil on the pad and lightly mix with your finger. Use this to rub out your shellac. It will redissolve the shellac and lay it right back down but very smoothly. This is what you do for a French polish but you don't need to apply any more shellac if you are getting air bubbles.
 
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