My customer has a bathroom cabinet custom made, which was finished with shellac. Needless to say, every time a little splatter of water gets on it, she has to buff out white marks. I told her that was the wrong finish for anything exposed to water and that it should have been polyurethane. A little late for that now, and the guy who build the cabinet is nowhere to be found.
So anyway, she want’s to know what I could do to fix it and I’m thinking strip off the shellac and refinish it with poly. But that’s a lot of work – sink base, medicine cabinet, and 2 doors (one on each). So… can I take a short cut and simply use poly to protect the shellac?
~ Ted W ~
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See my work – TedsCarpentry.com
Replies
Ted,
I'm no expert, far from it, but I think the old saying goes "shellac sticks to anything, anything sticks to shellac..." so I think you would be fine going over it after a scuff with a Scotchbrite.
You should ping Sphere for an expert opinion.
- Kit
ping
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Thanks K-
My train of thought is that shellac is a hard finish, as is poly. I know that you can't poly over old oil based varnish because the later is not a hard finish, thus causing alligatoring (like ice sheets on water). I think I'll be okay to poly over the shellac, scuffed as you suggested. But I've learned to ask the pros first.
How do I ping another member?
[ edit: oops, nevermind. Thanks Rez =) ]
~ Ted W ~
Cheap Tools - BuildersTools.netSee my work - TedsCarpentry.com
Edited 3/1/2009 11:47 am by Ted W.
Technically, yes you can. Albeit most poly is self sealing and it is not recommended to be used over a sealer or shellac.
If it were I, I'd shoot it with lacquer.
It will burn in better due to the hotter solvent. Poly doesn't have that and will tend to delaminate if it gets a ding.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
Hmmm... didn't think of lacquer. By shoot it, you mean spray it? I don't have a sprayer. Also, I understand brushing lacquer is an art in itself. I've never done it and not really into learning on the job, due to too many costly lessons in the past.
My other inclination is to leave it alone, but I need the work. So I should be safe with poly if it doesn't get dinged? I ask because the HOs are older and not likely to be knocking things around in the powder room. ~ Ted W ~
Cheap Tools - BuildersTools.netSee my work - TedsCarpentry.com
Polyurethane will stick well to shellac. Be sure to wash the surface with Naptha just in case there might be a coat of wax over the shellac. Unless you can take the cabinet out I'd avoid the lacquer (unless its waterborne). The smell lingers in the air for days (even weeks) and is bound to make someone sick.
The smell lingers in the air for days (even weeks) and is bound to make someone sick...
Yeah, that's another thing I was thinking about. I've used lacquer thinner to clean paint brushes before, and gave me a headach like I was wacked with a hatchet.
While I appreciate that suggestion of using lacquer for a more durable finish, what I need right now is the quick and simple solution. If poly will do the trick, then poly it is. ~ Ted W ~
Cheap Tools - BuildersTools.netSee my work - TedsCarpentry.com
Well, if you can brush poly or shellac, you can brush lac. But, go head and use the Minwax waterbased Poly-crylic , it has more compatable esters than oil based regular poly.
I'd use one of them pads with the real short little bristles, that lays down the Poly-crylic real well.
As an aside, you can get clear lac. in rattle cans, but I find them harder to control than a 35 buck sprayer from Cambell-Hausfeld.
DO scuff sand and wipe down with a damp rag first. I'd think 220 scuff would be best.Spheramid Enterprises Architectural Woodworks
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They kill Prophets, for Profits.
If there is really that much water, he could go to spar varnish. I'm pretty sure it will go over shellac ok (clean the surface of course).
Yep. Varnish (long oils) plays nice w/shellac.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
D'OH AGAIN!
I flipped the door over after putting a first layer of shellac on one side and discovered some stain had dripped down to the other side and dried overnight in two spots. I wiped them down with mineral spirits, then used wet sandpaper with the stain to try and feather the color back together again.
1. Any tips here on making stain match itself if doing a repair? No other coatings on this side yet.
2. After touching up this spot, do i still have to wait another 24 hours before I can shellac this side?
I will get to polying soon over shellac - I promise!
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
for future reference, lets prevent this problem instead of fixing it.Finishing doors - I run four 3" screws into the top and bottom of the stiles about an inch or so. Those seat on my sawhorses and I can flip and do both sides at one time.Some guys put one screw dead center and the other on an outer corner. This saves space as they flip right in place, but you need clamps to hold them in place.Another way is to have a eyescrew to seat in the top center and hang the door from a rafter in the garage where it can pivot. Then you need another at bottom corner to tie a wire or cord to so you can control swinging.With any of these, you can easily get all the way around the door and do both sides at once.other than fiddling and rubbing, I don't have the immediate answer to fixing things now, but I knew you'd appreciate a chance to use another screw or two.
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Ahem....
Exactly what kind of screws do you use for this task?
GRK
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Congratulations!
Mike_Maines receives the BT 'Knew Someone was Going to Say That' Award.
Saaalute!View Image View Image
Wow, my first award! The question did have to be asked....
grrrrr
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:->
LOL to myself... just watching how this thread is wandering. Typical BT! =D
btw, the cabinets came out real nice. Scuffed the shellac with a fine sanding sponge and applied 2 coats of satin poly. Looks great!
~ Ted W ~
Cheap Tools - BuildersTools.netSee my work - TedsCarpentry.com
Edited 3/6/2009 2:01 am by Ted W.
I already do that! I think I got that tip here awhile back, don't remember. BTW, I use the McFeelies #10 3" screws. Same diff.
This is a great idea, I'm going to have to switch to this method! That was my problem, I thought I had that other side done as far as wiping it off. I needed to double check it.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Overall: You want to make sure everything (colorwise) is set BEFORE you shoot your lacquer. After the lacquer goes down, you have far fewer options.It's pretty tough to get stain in under your finish. You have two main options:#1: sand the door that was already shellacked, stain it and reshellac.#2: tint your shellac for door #2 to make up for the lack of stain relative to door #1."Transtint" dyes are prety much the industry standard. Just add a few drops and see how it looks.The problem with #2 is that your color is setting on two different levels. The first door is dyed at the wood surface, while the second one is dyed at the finish layer. Even though it's only a few mils apart, it often makes a big difference.If you go this way, make sure you compare the doors in a variety of lights - daylight, incandescent, fluorescent - because different dyes can appear different in different lights (it's called metamerism).If your stain is water or alcohol based, you should give it a good day to set before you hit it with an alcohol-based finish (shellac) or it might bleed or worse, lift up.Another option for blending tones would be to match the color as best you can (or not), then rub on a gel finish (Bartleys). The gel finish is pretty forgiving, especially applied over shellac. You slather it on, let it dry for a minute or so, and then wipe off the excess. The harder you rub, the more that comes off. This lets you fine tune the color for any hard spots. You'll want to let the gel finish cure for AT LEAST a day before spray finishing (It would be 3 days to a week before brush coating).Finally, you can use tints in your lacquer as well. In all of these things, the underlying fact is that you can always make things darker. A final thought - you might try to lift the shellac off the unstained door by using ammonia. Shellac is pretty soluble in ammonia, and once it airs out, the wood should again take stain pretty well.Good luck.-t
Yer right about ammonia, but it's hell on oak or other tannin rich woods...it WILL darken it considerably, google "Fumed Oak" for more info.
Wanna remove shellac alcohol is still the preferred way.Spheramid Enterprises Architectural Woodworks
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They kill Prophets, for Profits.
Yeah, but doug fir is relatively low in tannins. It shouldn't be a problem, and if it is, a quick wipe with oxalic acid (usually sold as "deck cleaner") will bring you right back to ground zero. It's tough to remove all of the shellac with alcohol - as a practical matter you're just thinning it out. Ammonia does a better job of picking it up.A cool trick is to take low tannin woods and "prestain" them with tannic acid. A hippy way to do this is to wipe the boards down with a strong black tea.After it dries, you fume with ammonia and get the same effect as fuming tannic woods like oak or mahogany.The funny thing about fuming wood is that the color is never apparent until after you apply your film finish...-t
Actually my goof was on the door side that did not yet have any shellac on it, thankfully! Thank's for those tips, BTW. This thread is going to be a goldmine of good info for people... especially if I keep mucking it up!
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Brushing lacquer is speed & finesse. I did many trials with it before getting it right. No interruptions and a 'brushing plan' is good, also don't use a brand spanking new brush without combing it out first as to do away with any stray bristles. Use a quality fine brush. immerse the brush well into thinner, spin it almost dry, and you're good to go.
Load the brush, not too much, once over is all and barely lap the joints.Personally I like to spray the stuff.
A light scuff sanding with 150 or 180 first and you are good to go. Maybe tack it with some thinner in case there is wax.
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I find this topic very informative, as I'm just about to get started on finishing a pair of Douglas Fir 1 3/8" doors for my bathroom. They will be pocket doors, one slab will be next to the shower.
I've got one slab stained already, and I was considering using shellac over the stain, then a semigloss water based Minwax poly over that.
I have a .0511" HPLV spray rig I initially bought for auto painting awhile back but never used. All the resources I'm seeing say that you need to spray clear finishes with a .011" tip. I'm a little confused if I can use this setup for spraying shellac and/or poly, if I need to get a different gun, or if I should just use a brush instead.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Conversion gun or turbine?
Try the tip and adjust the air flow , if it won't atomize, you may need a finer tip. What brand gun it? It may be interchangeable with other brands or contact the maker and see whats available.
I've sprayed a lot of differet finishes with a lot f different rigs, depending on the conditions, you might be fine.Spheramid Enterprises Architectural Woodworks
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Here is the gun I have. Another thing I saw in the articles was a requirement for tip pressure to be 1000PSI. I have no idea what these things translate to, nor if they have any meaning with water based vs oil based finishes.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
That gun uses 2-3 times as much air flow as most portable compressors put out, so you will have to work in slow short passes. That is one of the problems of using a conversion gun. My HVLP runs off a turbine.
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Got that right, huge air hog. I spray conventional at about 35-40 psi and if its a big job, have to let the comp catch up..and its 40 gallon. Sometimes if I remember, I'll hook all the hose I can muster ( about 400') and gain a bit more reserve..LOLSpheramid Enterprises Architectural Woodworks
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That'll do fine if you can kkep it fed with enough air. Just dial around the mixture till it won't sputter and yer good to go.Spheramid Enterprises Architectural Woodworks
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for immediate coverage, you want to be sure and buy dewaxed shellac to use under poly
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I bought the Zinsser Bulls Eye SealCoat "Universal Sanding Sealer", for use under all clear finishes, 100% wax free!
Slow and short work is all I do, apparently. Just ask my wife. :)
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Yes, dewaxed is the key.
John
Hi Paul - I think you're about to make this thread even more interesting.
I wouldn't mind getting a spray setup. I have a nice space for a small booth, would be ideal for small projects (night stand, jewelry box, etc..) so I'll be watching the replies.
Thanks for posting! =)~ Ted W ~
Cheap Tools - BuildersTools.netSee my work - TedsCarpentry.com
OK, I finally found my balls and decided to put a little shellac on the bottom of one of the doors to see how it worked out. I'm now waiting 30 min to see how it looks.
I went ahead and used my gun, I set the pressure on the regulater to 40, with the 1.4mm tip. I didn't play around at all with the settings, it looked like it was atomizing, and I couldn't tell what kind of finish it left because it sucked into the bare wood I sprayed. It's warm and dry today, so conditions should be just about perfect.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Just sprayed the 2nd layer of shellac on the first door. Now I wait 24 hours before I sand and put the first coat of poly on.
One thing that surprised me about DF: how much it likes to grab cloth if you go against the tooth of the grain! I had to pull out a half dozen tufts of pulled fabric when I went the wrong way from wiping the stain on the wood.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Its a hard wood to mill - very splintery
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Rookie here makes another mistake:
After applying the wood conditioner then staining the first door, I got so wrapped up in the shellac bit that I forgot to use the wood conditioner on the 2nd door. D'OH! We'll see if they look dramaticly different.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
You were probably distracted with a rookie teckie on some PC hardware.
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Well, It's been cold and rainy off and on for the last couple days... I finally got a few more coats of shellac on today, enought that I can now sand without burning through. Hopefully I can sand it tomorrow and lay down the water based poly. My air compressor has been dying too, so I'm going to try to pick up a craigslist special - 60gal, 5hp for $250.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Just a quick question about sanding:
I put about 4 good coats of sanding shellac on, and I'm wet sanding with 240 grit on the random orbital. This is what I have so far...View Image
As you can see, I've sanded off the high spots. Do I need to get down to the low spots too? Should all the shellac be sanded to the same even layer (i.e. no shiney spots), or will the multiple coats of WB poll even it out some?
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Dude, what ever posessed you to wet sand shellac? That is really not a good idea, unless it is the final finish and you use an oil and not water.
I say stop. If you want it more level, which you already have too much on ( IMO) you need to build the poly and level it. THAT can be wet sanded..without problems.
Wet sanding is Generally for the final coat(s), and the finish has to be one that gets hard enough to sand to that level of dead flat, mirror like.
One, coat of shellac sealer , thinned would have sufficed..de nub that and go with the higher build coats of the final finish.
I have to suggest you may want Bob Flexner's book "Understanding Wood finishing" It will help you immensly.
Spheramid Enterprises Architectural Woodworks
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They kill Prophets, for Profits.
Edited 3/16/2009 3:29 pm ET by Sphere
I'm going by the article "Clear Wood Finishes" by Byron Papa. Looking back at it, he says to dry sand wood with 220, then wet sand the finishes starting with 320.
From reading all around, it sounded like the Poly was the more difficult finish to get right, while shellac you can build, sand, repeat - until you have the surface you want. Poly sounds like you have 24 hours then you're frakked as far as fixing anything.
So you are saying that I can build, sand, repeat - WB poly?
PS - what "oil" would you sand with?
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Edited 3/16/2009 4:04 pm by xxPaulCPxx
Build , sand wb? Yes, you can. Depending the final results wanted you can just dry sand between coats, I save the wet for the end IF needed..Unless I'm doing a really high end finish, I don't need to sand after final spray. Maybe buff with scotchbrite and wax..wet sanding is for pianos and cars and guitars.
Water , oil, soap, all work to keep the paper from clogging up..thats really the reason for wet sanding. But Shellac and water is a no-no. It can and will absorb the water.
I use mineral oil, if I wet sand w/oil..but thinned poly, or varnish can be used as well..but once you get oil involved stay away from WB over that, M.Oil doesn't cure or polmerize..it's a last step before wax or just the last step.
Spheramid Enterprises Architectural Woodworks
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If using shellac for THE finish, you can build lots of coats, but when using it for just a sealer, one or two coats is plenty. I have never done wet sanding
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Paul, When I'm laying shellac down to be covered by a more appropriate top coat, I don't sand. I use a utility knife blade held just about perpendicular to the surface and scrape.
All I'm looking to do is knock down the tits (as Piffin calls them). The next coat will then build up and fill in any depressions. A couple of these and it's real smoooth.
I'll scrape and sand betwixt poly coats for the adhesion properties gained coupled with the #### reduction.
Thanks everyone for that last bit of advice. I touched up a couple of burn through spots yesterday (sand in some stain and let dry 24 hours... again), and today is a perfect day for spraying. Little breeze, 80 degees, dry.
BTW, I was spraying the Zinnser wax free sealing shellac, uncut. I liked the way it looked after I went over it with the alcohol to clean up some spots after sanding - I think I'll use that for something on a different project.
I just applied my second coat of poly. The first one laid out reeeeeaaaaaalllll nice. I'm so used to doing it poorly with a brush, I had no idea it could go this well! I see what everyone was saying now about not fussing with it as much as I was.
I think I'm going to be very happy with the results!
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Edited 3/18/2009 2:50 pm by xxPaulCPxx
I'd be using something like 180 gtit or possibly 120 for something that pickled and rough and I never use the orbital for the between coats sanding, even on floors. Hand sanding lets the paper float and work the surface better.I suspect the uneven texture is because you are spraying the shellac and it is such a volatile carrier that it is trying to dry tooooooo fast, partly dry droplets atomized in the heat of the gun and falling thru the air land and cling to each other but don't flow and spread smooth.So by hand sanding with the grain, and then brushing on a coat ( maybe with more alcohol cut to remelt what is there - how much are you cutting this stuff???) brushing with the grain you should be able to get a mirror smooth face.
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I don't know anything about the Minwax WB Poly but I have done a fair amount of shellac (the Bulls Eye sealer) as a base for Target WB finishes from Homestead Finishing.
The biggest challenge I had was shellac build-up on the edges from a little too rich mixture when spraying the sides. I do a light sand on the shellac - I think with 220 - before moving on to the top coat. 2-4 coats of top coat.
I used the Target WB pre-cat conversion varnish for the kitchen and it's held up quite well to water and other abuse. Burns in very nicely between coats so no sanding needed. Downside is short shelf live; Homestead has stopped carrying it for that reason.
I've shifted to the Target Hybrivar Varnish and really like how it sprays and burns in. Also has a warmer look than your typical WB products - really looks like an oil-based finish.
My conversion HVLP came with a 1.3 (shellac) and 1.7 (the thicker finishes).
It's funny how painting has this whole different lingo that I han't stumbled on before. For I and the other spray finish newbies here, could you explain a few things for me from your post?
What is pre-cat conversion varnish?
What does burning in mean?
I'm putting you on the spot here because you are using the same wording that I read in a bunch of other places on the web. I must plead total ignorance though, please help me learn this lingo!
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
OK, this will be a bit like the blind leading the blind - LOL. I'm sure when I get it wrong there will be plenty of more knowledgable folks who will be happy to correct me... (God bless Google!)
What is pre-cat conversion varnish?
What does burning in mean?
Hope that helps!
I like to use their Oxford WB spray lacquer. However, I last used it in a occasionally damp area (around the kitchen sink) on our kitchen cabs. Over a couple of coats of Watco, then shellac, then about 4 to 6 of the Spray Lacquer. I get whitish spots from the water.
You think another coat of Spray Lacquer may help with those spots?
Pete, no idea how to address the spots. The best person to ask would be Jeff Jewett @ Homesteadfinishing. He has always been incredibly helpful whenever I've spoken with him.
If you still want to try lacquer, Deft makes it in a spray can. For the size job you have, it might be the way to go. I use it on small turnings.
One nice thing about lacquer is how fast it dries. You can apply multiple coats very quickly.
Frenchy couldn't be here so I am filling in:
The best finish for anything, at all, ever, is shellac. It's the greatest for floors, decks, chain saw sculptures, fine furniture and antique taxidermy. It also makes a delicious smoothie.
Sure, denatured alcohol melts it like ice, but I use it on my eczema, my wifes collagen, and have it implanted in my #### cheeks. It always works great! I shellacked both of my children and they are now, (somewhat sticky), honor students!
I just love saying 'shellac, shellac, shellac'! It's fun to type it too.