Dye is still coming off through the Nitro Lacquer

[KevinTJH]

I previously used a water-based red dye on bare wood. I sprayed about 13 coats of Nitro lacquer over (no sanding in between) it in hopes non of the dye would come off from wet sanding later on.

 

 

I have allowed the nitro to dry for a full 7 days. However, when I used a small wet tissue to touch the guitar as a test patch, there is still plenty of dye coming off.

If the dye is coming off from water, I can't imagine how much damage sweat would do to it.

 

What's going on here? Do I still need more nitro coats?

 

Please advise as soon as possible!

[DeepEnd]

I've never worked with nitro but even I know it takes a good while to dry completely, not just a few days, longer depending on how thick the finish is. My guess--and that's all it is--is that the dye mixed in with the nitro so that you're rubbing off finish, not dye. I'd let everything dry before you do anything else.

[KevinTJH]

I've read so much conflicting information about nitro, I'm not even sure what to believe. Someone posted on an online forum that Nitro "never cures" because there is no chemical reaction or change, and the layers just keep on blending onto itself.

 

I didn't use any sort of sealer.

Just the red dye, sand, red dye, sand, and another layer of red dye. After that dried for a day, I sprayed 13 layers of nitro over 2 days.

 

I've done some very very light dry sanding with 1500 to make the whole guitar smooth and there wasn't too much red on the sandpaper.

But this guitar still isn't "waterproof" and the red colour still comes off from wetting it.

[Freeman Keller]

 

Someone posted on an online forum that Nitro "never cures"....

 

I didn't use any sort of sealer.

Just the red dye, sand, red dye, sand, and another layer of red dye. After that dried for a day, I sprayed 13 layers of nitro over 2 days.

 

Thats actually true - lacquer is an "evaporative" finish (as is shellac and spirit varnish). These are different from "reactive" finishes which include most of the oils and catalyzed finishes. The third kind are "coalescing" finishes which includes most of the so called "water born" lacquers. There is no reaction with lacquers - the solvents continue to gas off for a long time. Since there was no reaction a new coat will blend ("melt") into old coats - one of the great benefits of lacquer.

 

Most people spray a barrier or seal coat over their stains to lock them in - vinyl sealer and shellac are the most common. Water based stains bleed less into lacquer than alcohol based stains, but they still bleed. In fact if you go way back to your question about candy apple finishes you might remember that one of the recipes used by Gibson and others is to stain the wood then apply clear over that with the intent of getting the color to go into the lacquer.

 

I have not heard of the kind of bleeding that you describe but then I've never applied as much stain as you have. I put light applications on bare wood to highlight the grain and give me some background color. Then I shoot colored lacquer followed by clear but haven't seen anything like you describe. My usual finish schedule is

 

Note one thing important about the way I do it - I'm not trying to get color with the stain, its to pop the grain and give a little background. I do most of my coloring in the lacquer itself. I've never felt like I had very good control over stains like I do colored lacquer.

 

I would let it cure a few days, sand 320 or 400 and shoot a couple of more coats.

 

If you happen to be interested in one of my red guitars, the finishing starts on page 4 of this thread

 

http://www.harmonycentral.com/forum/...ther-335/page4

[KevinTJH]

Thanks for the response. I was going for more of a Satin Finish though as opposed to Gloss. I'm honestly very very happy with how it looks at the moment and wouldn't change anything about it. The only thing I'm worried about is the colour bleeding from moisture.

 

How do I fix that at this stage now? Would more coats of Nitro work?

 

[WRGKMC]

Rule #1. You shouldn't mix your chemical types.

 

Water based and alcohol based finishes never work out well. I've seen many similar horror stories posted here over the years, especially with water based dies. You should have used a water based lacquer over the dye not nitro which is alcohol based. I have no idea how good the results would have wound up being because I don't mess with the newer water based acrylics, I stick with traditional methods of finishing. I've done some experimentations over the years after a few failures you heed the warnings woodworkers give for good reason.

 

You have Oil, Alcohol, Acrylic and Poly finishes. There's only a few that will work with each other and even those are questionable long term. The traditional are alcohol based. The way these apply are different then the others. Oils and polys go on in separate layers like layers of an onion.

 

Each new layer of lacquer melts into the previous layer to make one thick coat. This is why you're dye is leaching to the surface. You aren't sealing the dye below the surface, you're combining it with each new layer. The alcohol driers in lacquer re-melt the previous coats as the new coat goes on. The dye simply migrates to the surface as each new coat is applied. You should have sealed the dyed wood with a clear shellac which the lacquer couldn't penetrate.

 

The only true fix for you now is to strip it down and start over because there's nothing that can fix the issue at this point.

You may want to read up on that Dye too. It is likely recommended you use a water based lacquer, acrylic or poly over it. Often times the manufacture puts specific recommendations on their site and people are simply too lazy to read labels and directions.

 

All I can say is take this as a learning experience like I did. I don't have excuses for myself. I grew up with parents who refinished antiques and was told a thousand times over a 30 year span you never mix your chemical types but I tried it anyway and ran into problems when I did.

 

 

[Freeman Keller]

Can you tell me exactly what your finishing schedule was?

 

What is the "dye", how was it mixed and applied?

 

I assume you are using rattle cans of lacquer - is that correct?

 

Please don't do anything until you answer those question.

[KevinTJH]

Yes, it was Nitro from a rattle can.

 

Day 1 - Applied water-based dye, let dry for an hour, sand, repeat. Final coat of red dye dried overnight

 

Day 2 - 4 coats of Nitro lacquer, 30 minutes between each coat. 2 hours of drying on the 4th coat. Light wetsand on headstock. Stuck decal on, let it dey overnight.

 

Day 3 - Took masking tape off to expose fretboard. Another 9 coats of lacquer, 30 minutes between each coat. (Fretboard had a total of 9 coats, the rest of the guitar had 13 coats)

 

A week later....

 

Day 4 - Very light dry sanding with 1500 grit sandpaper on entire guitar. Freaked out about colour bleeding.

[KevinTJH]

 

Each new layer of lacquer melts into the previous layer to make one thick coat. This is why you're dye is leaching to the surface. You aren't sealing the dye below the surface, you're combining it with each new layer. The alcohol driers in lacquer re-melt the previous coats as the new coat goes on. The dye simply migrates to the surface as each new coat is applied. You should have sealed the dyed wood with a clear shellac which the lacquer couldn't penetrate.

 

The only true fix for you now is to strip it down and start over because there's nothing that can fix the issue at this point.

You may want to read up on that Dye too. It is likely recommended you use a water based lacquer, acrylic or poly over it. Often times the manufacture puts specific recommendations on their site and people are simply too lazy to read labels and directions.

 

All I can say is take this as a learning experience like I did. I don't have excuses for myself. I grew up with parents who refinished antiques and was told a thousand times over a 30 year span you never mix your chemical types but I tried it anyway and ran into problems when I did.

 

Oh my gosh... if starting again is not an option, are there any other alternatives? Any at all?

I've shot nitro over poly before and it's worked out good for me. I don't suppose you could do the opposite and shoot poly over nitro right?

 

Please let me know if there is another way of fixing this mess without having to strip the whole thing down.

 

This is only a personal guitar and I have no plans on selling it to anyone. So even if it's not the prettiest looking thing, I'd be happy enough if it's a playable and durable instrument.

[Freeman Keller]

Kevin, WRG and I are going to give you differing advice - that isn't unusual. One of your options is to sand back to bare wood, but you aren't even going to get there because the stain you applied has penetrated into the wood (thats why its called stain). However sanding to bare wood will also create its own can of worms - thats why I think its better to try to salvage what you have.

 

I'm going to guess that based on your schedule you (1) applied way too much stain and a lot of it actually was sitting on the surface, (2) you didn't use a seal coat which isn't unusual with rattle cans, (3) you applied way too much lacquer way too fast.

 

Rattle cans of lacquer have a higher ratio of reducer (thinner) to solids - it does not build as fast as the stuff from a spray gun. That means it will take more to get a level surface - the one guitar I finished with rattle cans I think got 24 coats. Second, the high proportion of reducer means that it went on "wet" and there was more of the effect of softening the previous coat. The solvent in the first few coats probably just sucked the "dye" from the wood and mixed it with the lacquer. By shooting as many wet coats as you did in rapid succession the earlier ones didn't get a chance to thoroughly cure (solvents didn't evaporate).

 

After one week you should be reaching an equilibrium - at some point successive coats will bond to the previous ones without going too deep. My suggestion is to wet sand with 400 or 600 and look at the sludge - if it is pink you are sanding into color. If it is fairly white you are sanding clear coats. Shoot a couple of coats and let stand a full day - wet sand again and see what color the sludge is. Continue to do this until its white, then stop and do whatever final prep you like.

 

This is what it should look like when you are sanding clear

 

 

It also looks like you didn't pore fill your guitar (I'm assuming the body is mahogany) and you said you want a satin finish. Normally gloss lacquer won't give you this - you may want to sand the final coat to about 8000 or 1000 to get all the scratches out, then go over it with your 0000 steel wool - that will do a fairly nice job of knocking the gloss off and giving you a satin finish.

 

 

[KevinTJH]

Thanks for the advice, Freeman. So I'm going ahead with your suggestion, the solution would be to spray even more coats of Nitro but space out the drying time much more? When I lightly sanded the 13th coat, there was still a little bit of pink on the paper, but it has definitely been alot less than before.

 

If I spray, say, 10-12 more coats of Nitro, but allowed each coat to dry for 12-24 hours, would this help fix the problem? Thanks!

[WRGKMC]

As far as putting poly over lacquer don't even try. It will peel right off the lacquer in large sheets. Been there and tried it.

 

I'd try what Freeman suggests (we do agree many times we just explain things differently based on our own individual experience)

 

I'd lay the instrument flat so the lacquer wont run and try putting on some heavy coats quickly and attempt to trap the dye below. Heavy coats have a tendency to run but the trick is to get the light angle right so you can layer it on to where you see the lacquer look like glass and stop just before it begins to run.

 

You can do this for the front and back but not on the sides for obvious reasons, the lacquer would run badly.

 

The only other alternative I can think of and have tried, is to put Tung oil over what you have now. Something like Minwax Tung oil is mostly varnish and will adhere to lacquer.

 

It does dry to a very hard finish and comes in both gloss and semigloss. The problem is it doesn't come in sprays and you'd need to apply it by hand. I usually use foam brushes to apply it in single strokes with enough liquid to give it an even shine. You don't want to do brush overs because it will loose its smooth coating.

 

Tung will yellow the coloring however. A bright red like you have now will take on an orange antique look. You'd have to decide if that's something you'd want to deal with but it would fix the problem because Tung goes on in independent layers.

 

You'd also have to apply enough to where you could sand out the flaws from hand application which is a pain in the rear too. Tung dries much harder then lacquer and is more difficult to buff up. I do like Tung for its durability however. Its as tough as nails but it doesn't have that plastic feel poly has, it even feels nicer then Lacquer in fact but it does take practice applying.

 

Many wipe Tung onto bare wood for a minimal finish look, but it can be built up in thicker layers to get the same look lacquer does. I usually use it on natural wood finishes because it does yellow, but it is twice as durable as lacquer which is nice from that aspect.

 

Again, my first suggestion is go with some heavy coats of lacquer and dong just dust it on. If you notice the heavy application turning white, that's about the limit of the thickness you can go. The white will disappear when it dries. Its simply moisture being trapped and will evaporate once the finish cures.

 

If you have no luck using only lacquer then again, you could strip it back down and start over.

 

I'd simply use paint remover. I'd have all that stuff off there in 30 minutes with no sanding involved. You dit heavy gauged steel wool in the pain remover and simply wipe the lacwuer away. Use a putty knife to take off the bulk of it. ,Afterwards you wash the remaining paint remover off, let it thoroughly dry, light sanding to open the pores, reapply your dye, seal it and re-lacquer.

 

I know this isn't what you want to hear so I'm not suggesting it - Its just how I'd do it.

 

Finishing is one of those jobs you either do right or you don't. I've done finishing for over 50 years and I hate it with an absolute passion, probably because I was enlisted by my parents to do antique refinishing as a young kid. I grew up with the smells of paint remover, turpentine, and linseed oil. I even painted out cat with linseed when I was three years old. Guess I was destined to deal with the stuff on an ongoing basis. If it weren't for guitar building, I'd never touch the stuff.

 

 

[Freeman Keller]

Thanks for the advice, Freeman. So I'm going ahead with your suggestion, the solution would be to spray even more coats of Nitro but space out the drying time much more? When I lightly sanded the 13th coat, there was still a little bit of pink on the paper, but it has definitely been alot less than before.

 

If I spray, say, 10-12 more coats of Nitro, but allowed each coat to dry for 12-24 hours, would this help fix the problem? Thanks!

 

 

If it was my guitar that is basically what I would do. Wait as long as you can bear - its been a week, give it another if you can. Then sand it thoroughly at about 400 - you want a dull red look all over the guitar. Sand out any orange peel, runs, sags, dust and scratches. You can wet or dry sand at this point, but get all the dust and sludge off the guitar. Wiping with naphtha (lighter fluid) is not a bad idea - it will take any oils off the surface. If you are wet sanding use a damp rag to get all the sludge off. Like I said earlier I don't trust those painting tack rags - they seem to leave something on the surface.

 

I would shoot a medium coat (appears wet and glossy but not too thick). I would definitely NOT try to apply heavy coats - they take a lot longer to cure and if you get a run you have to wait a day or two before you can sand it out. Shoot 2 or 3 coats a day 3 or 4 hours apart, then let it dry over night. The next day you can do it all again, sand to 400 or so, 2 or 3 medium coats. Stop when the sanding sludge is white and you are happy with the results.

 

Most people shoot guitar hanging like in your picture - I've started doing it flat. Its really hard to get consistent application while hanging - you are shooting up, down, every which way. I put a couple of blocks of wood on a small table that I can walk around and another in the bridge pickup hole that sticks out a half inch or so (I'd show a picture except that Photobucket is down right now). Anyway, put the guitar on its back on two blocks and shoot the top, peghead and a light coat on the sides shooting down at about 45 degrees. Let that cure for 15 minutes and you can gently pick it up and set it on the pickup block and one under the fretboard. Now shoot the back, neck, back of peg head and sides (again, lightly). Since you are using rattle cans and don't have to clean up you should probably wait longer before flipping it over.

 

Basically when I'm doing it that way I'll walk around the guitar shooting the sides, then I'll shoot the top or back across the guitar - that way I don't get an excess at the edge. Fill in the middle, do the neck and head and bingo. I started doing this when I was trying to learn sun bursts, now I do all my finishes that way.

 

The other thing that I'll add is that I would not put anything else, poly, Tung oil or anything on your guitar (doesn't putting oil on lacquer violate Rule 1?). I've never tried it so I don't know that it won't work, if you decide to do then practice on scrap.

 

I think you can salvage this if you take your time.

 

edit to add - here is a picture of a guitar being finished. It is sitting on some little wood blocks on a low table

 

[WRGKMC]

^^^ Tung oil does stick to lacquer. but I couldn't tell you how many decades it will last. I've done some maple necks applying Tung over lacquer over lacquer and they have held up 10+ years so take that for what its worth.

 

Its not my best advice for this project, I'm simply stating its the only thing I know of that would stick to lacquer and it does have consequences with application and yellowing. It does give it an antique look however if you were trying to intentionally make a neck look vintage.

[KevinTJH]

Thanks for the help, guys! I'd probably stay away from Tung oil as I am already exceptionally happy with the red colour (took me a while to find the perfect dye), and it would be pretty sad to change the colour to fix a mistake at this stage.

 

I will do as Freeman suggested about spraying more lacquer. However, is it really necessary to sand to 400 after only spraying 2-3 medium coats and a day of drying? I'm worried I will continue to lose even more red from sanding so early. What about doing the whole spraying and drying, but only start sanding after the 5th day or? Then I'm assuming there will be bigger barrier of lacquer on the red dye?

[Freeman Keller]

I will do as Freeman suggested about spraying more lacquer. However, is it really necessary to sand to 400 after only spraying 2-3 medium coats and a day of drying?

 

Kevin, you can do it any damn way you want. I'm telling you what I would do. Of course I'm also trying to get a perfectly level and flat surface - you've said that isn't important. Also, don't forget that I would have done it differently up to this point - I'm trying to help you salvage the fact that you ignored my previous suggestion.

 

Back in my street rod days when we painted cars with lacquer we used to put on 20 or 30 or more coats and sand it until it was perfect. We used to say that most of the finish went on the garage floor. However today people build rat rods and paint them with a brush.

 

[badpenguin]

Kevin, do as Mr. Freeman suggests. Yes, you will lose 6 coats out of the 10 you spray. That's the nature of the beast to build up a proper finish. And for clarification, a proper finish means no bumps, no divots, a clear shiny finish all over the guitar.

Compare a faded SG, to a Standard one. Mr. Freeman's method will give you a Standard. And, something to be proud of, IF you take the time.

[KevinTJH]

Thank you!!