Yet another shellac problem

[Scott Hearn]

Using Zinsser Bullseye clear on a kids table. I refinished it with Sherwin Williams BAC wiping stain. Then I shot a coat of aerosol Zinsser Bullseye on it since the BAC stain doesn't like to be wiped or brushed, it's mainly for spraying a topcoat over but I wasn't wanting to spray on this project.

I think the aerosol is where the problem starts. It was very orange peely no matter how heavy a coat I put on it and sanding it doesn't seem to help. It's also quite easy to get into the stain with the sanding. After one coat of aerosol I put on a coat of the Bullseye cut with DNA to about a 2lb cut. It seems that no matter how many coats I put on I just can't get the stuff to level out at all whether sanding between coats or not. I've cut it back to a 1.5lb cut in an effort to get a nice smooth finish. I'm using a Purdy natural bristle brush and getting decent results on a piece of bare scrap wood with it, at least better than the actual project.

I'm at the point of starting over because it looks terrible. As a last ditch effort would shooting a coat (or five) of straight DNA with my small HVLP gun get it to level any? I'm about to break out the sander again...

[Jim Becker]

If you are applying the shellac like varnish, you're going to have issues. Shellac is an entirely different animal than varnish. With the latter, the goal is to build up the finish to a certain thickness to provide the protective properties and so forth. With shellac, the goal is to apply as little finish as possible to make it look nice. Shellac doesn't like "thick" and too much thickness leads to problems like cracking, crazing, uneven surfaces, etc. You also cannot work the finish like you can with varnish...it gets tacky really quickly. Put it on with a quick stroke and move on with the wet edge. Do not go back over where you already applied the finish and "tip off". Working shellac is an art-form, but once you develop a feel for it, it's a wonderful finish to use.

BTW, with the Zinsser shellac in the spray can, the same thing applies...very light coats. Never heavy with any pooling of the finish. It's better to spray on 2 or three really light applications than one heavy one.

[John TenEyck]

I mostly agree with what Jim said. Your problems started by spraying too heavy a coat. You should spray light coats, just enough to seal the BAC stain. Your approach for brushing additional coats on should work fine once you resolve the initial problem. If you need more open time use Behlkol instead of DNA.

At this point I don't see a good alternative other than sanding/stripping everything off and starting over.

John

[Scott Hearn]

Thanks guys. This is my first foray into shellac. I can sure see why some still like it as it imparts a very nice visual to the underlying grain and the dry time is awesome. I'm going to go back to what I know and spray some Endura-Var after restaining. I'll go to shellac for smaller projects.

[Jim Becker]

Scott....practice applying shellac (or any other new-to-you finish) on less important things than your special project. It's not an expensive finish and it really does take a bit of time "in the trenches" to get comfortable with applying it and breaking the "varnish habits".

[Mel Fulks]

Agree. Forget any similitude with painting ,you have to put on like the house is on fire. And it's not unusual to thin it
more than what you have now.

[Martin Siebert]

I too have had all the same problems with shellac, and agree with everything I have read here so far. Thankfully, I only had to use it once when I had no choice. I was matching a finish and there was just no other substitute. I used it to match something, but my question is, other than to match something because you have to, what is the reason {or maybe advantage is the right wording} anyone would use shellac??? Maybe I am wrong, but it sure seems like to me that it is difficult to use, compared to many other finishes it's not particularly beautiful, it doesn't necessarily hold up and cant really be considered "superior" in this regard...why does anyone bother to use it???? I have to be missing something.

[Stan Calow]

Martin I like shellac for a number of reasons. Its easy to fix, seals in problems, dries quickly, and I think it can provide a nicer less plastic-looking surface than poly. Its hard enough for most purposes. Others may provide other advantages. But its not always the best choice.

Jim,

"With shellac, the goal is to apply as little finish as possible to make it look nice. Shellac doesn't like "thick" and too much thickness leads to problems like cracking, crazing, uneven surfaces, etc."

I've never heard a better and more useful explanation than that. Thanks.

[John TenEyck]

Thanks guys. This is my first foray into shellac. I can sure see why some still like it as it imparts a very nice visual to the underlying grain and the dry time is awesome. I'm going to go back to what I know and spray some Endura-Var after restaining. I'll go to shellac for smaller projects.

Scott, I've used quite a bit of BAC + EnduroVar, but I always spray a light coat of Sealcoat shellac over the BAC first. Unless you already know that EnduroVar is OK directly over BAC, you should make a test panel to confirm it will bond OK.

John

[Scott Hearn]

Scott, I've used quite a bit of BAC + EnduroVar, but I always spray a light coat of Sealcoat shellac over the BAC first. Unless you already know that EnduroVar is OK directly over BAC, you should make a test panel to confirm it will bond OK.

John
Thanks!

And I have used EV over BAC on my kitchen cabinets. No problem in 6 years. The key is letting the BAC dry totally and completely. ETA: I gave it a full 24 hours or more when other things were going on.

[John TenEyck]

That's good to know, Scott. Six years, no problems; proof enough for me. Thanks.

JOhn

[Martin Siebert]

Martin I like shellac for a number of reasons. Its easy to fix, seals in problems, dries quickly, and I think it can provide a nicer less plastic-looking surface than poly. Its hard enough for most purposes. Others may provide other advantages. But its not always the best choice.

Thank you sir for the reply. I have to admit to having to use it a little differently. I had to match a particular finish that required it to be put on multiple times {thin, because I quickly realized this was the best way} to get the end color right. I used Zinnser and I think the color was amber. It was nice that it dried so quick and you can go ahead and fix a run or bad spot, but it was still a pain until I got finished.
I have always wondered if there was some specific wood working projects in which shellac was the "traditional" correct thing to use.

[David Bassett]

... I have always wondered if there was some specific wood working projects in which shellac was the "traditional" correct thing to use.

I think (very) old furniture is the iconic example, but classical guitars are another example. E.g:

Hill Guitar: About French Polish (http://www.hillguitar.com/website/news/tech_notes/french_polish.html)

(PS- Kenny Hill isn't a chemist. I'm not sure shellac is generally considered a varnish.)

[John TenEyck]

I think (very) old furniture is the iconic example, but classical guitars are another example. E.g:

Hill Guitar: About French Polish (http://www.hillguitar.com/website/news/tech_notes/french_polish.html)

(PS- Kenny Hill isn't a chemist. I'm not sure shellac is generally considered a varnish.)

I didn't look at the link, but your comment about shellac not being considered a varnish caused me to remember that long ago "spirit varnish" was used on musical intruments and furniture. Spirit varnish has many iterations, but AFAIK all are shellac based plus additives. Today, varnish has a different meaning - an oil and resin that are cooked to form a new compound, but that was not always the case.

John

[Martin Siebert]

I think (very) old furniture is the iconic example, but classical guitars are another example. E.g:

Hill Guitar: About French Polish (http://www.hillguitar.com/website/news/tech_notes/french_polish.html)

(PS- Kenny Hill isn't a chemist. I'm not sure shellac is generally considered a varnish.)

Thank you sir, I kind of thought it might have been used for old furniture or new stuff trying to be traditional. I never knew or thought it was used on instruments. Makes me wonder if it was used on old violins and if it might have attributed something to the sound quality.

[Jim Becker]

Thank you sir, I kind of thought it might have been used for old furniture or new stuff trying to be traditional. I never knew or thought it was used on instruments. Makes me wonder if it was used on old violins and if it might have attributed something to the sound quality.
Finish absolutely has an effect on tone-woods and makers always have had to be very careful about that. Shellac is almost an ideal finish because of it's nature as an evaporative product which can be put on in very, very thin coats that then become one single layer.

[Prashun Patel]

If it were me, I'd wipe the surface down with DNA several times to level the shellac. Then I would spray a couple thinned coats.

I suggest this only because it will save you the headache of sanding and restaining - which can be a problem on already-stained wood. Also, if you have the ability to spray Endurovar, you have the ability to spray shellac. Spraying shellac is super easy. Just keep the cut thin. I also suggest instead of Zinsser Bullseye, you use Sealcoat. It's already thinned and dewaxed, which gives you more options if you decide you want to topcoat with something later.

[Jerry Lowetz]

The difference between shellac and a lot of finishes is shellac will re-disolve. So you put it on very thin, following coats will level.

If you're spraying/applying trying to get each coat level, you're probably putting it on too heavy.
Go for thin. Spraying it may even be rough, if it were paint it'd feel like sandpaper and you'd spray heavier, but with shellac, the next coat will re-dissolve and smooth.

If it's your full finish, after some depth you may smooth it out a bit with a light scuff between coats, but the alcohol/solvent will do some levelling and flooding every coat to level prior coats.

Source: I've overapplied a lot of shellac learning. Then there was the day I thinned so much that a dozen coats and no buildup, that didn't work well at all either. From that, I met in the middle and it's been working well since!

[Phil Mueller]

Regarding the question, why use it?, I use shellac for all interior applications like drawers and boxes. Oil based finishes on interior surfaces seem to smell for decades. But I have also used it as the exterior finish. I like the depth it seems to give wood.

As others have said, it takes some getting used to. While trying to perfect french polishing (which I’m still working on!), my failures are usually caused by too much shellac. It’s one of those if it looks good, stop. The temptation is if a little looks good, more should make it look better...and that often isn’t the case.

[Jerry Olexa]

Good advice above...Shellac goes on thin (no build up needed).....A little DA on rag will help correct your old issue of the thick coat..

[Peter Kelly]

I'd suggest mixing your own with some de-waxed flakes and 190 proof Everclear. Shellac itself comes in a myriad of different grades and I'm guessing Zissner probably uses what makes financial sense rather than the best possible product. Once mixed, shellac also has relatively short shelf life and I've noticed that the hardware store stuff doesn't seem to indicate a sell by date. Would definitely avoid. Even dry de-waxed flakes themselves only have a shelf life of a few years.

Shellac is an excellent finish for many things, just takes a bit of trial and error to get it right.

[roger wiegand]

If you started with shellac it's the other stuff that "takes some getting used to" and "requires a lot of trial and error" to get right. Just a matter of perspective. I was shocked at how long other finishes took to dry-- gathering bugs and dust the whole while. Shellac is a great sealer for making wood airtight in organs and automatic musical instruments like player pianos. It's a real benefit to be able to hit it with a fresh coat, re-melt what was there before without having to sand or strip and have a like-new surface. The benefits in many ways parallel those of hot hide glue. Rebuilding old instrument done with shellac and hide glue is real pleasure compared to the nightmare of modern glues and finishes in that setting.