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Finishes Not Drying Hard


jazzman22

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Hi all. I'm a new user and this may be a common question, but I'm having the worst time with clear coat finishes!

I'm fixing up an old Les Paul copy for a friend. I stripped and filled the wood, primered it, did the paint, polished it a bit, and it looks great. Naturally I wanted to put a clear coat over it to protect the paint, so I used a spray lacquer (Painters Choice... Green spray can) that looks great when it dries. I let it sit for a day or two to harden and then put the body on a soft clean towel to lightly polish it and buff it up before assembling everything. I polished the front, and when I went to flip the body over I noticed that the towel left marks all over the back of the body IN THE FINISH! The first thing I did was switch towels, flip the body over, lightly sand out the marks with very very fine sand paper (1500 grit) and then tried to polish it up. And thats when I found that the new towel left marks on the other side of the body now as well! :D

So I sanded the body to get some of the lacquer off, cleaned it, and then tried respraying it with a few light coats. I let the whole thing dry for over a week... and had the SAME PROBLEM (towels leaving marks IN the finish)... So I sanded the lacquer off and decided to try enamel instead... I sprayed the body, waited 4 or 5 days for it to completely dry, and ended up with... THE SAME PROBLEM!

In a frustrated fit I sanded the enamel off and decided to go with polyurethane... anyone want to guess what happened? If you said "THE SAME PROBLEM" you'd be right... and it's not just leaving tiny, almost invisible marks in the finish, it's really texturing the finish! I know it's not the towels, they're all clean and there were no chemicals, fabric softeners, etc used... just tide and other than that they're clean. Anything I rest the body on leaves a mark in the finish.

I asked at a few paint stores and got a lot of blank stares, but one guy who seemed to know what the was talking about mentioned that I should let the polyurethane dry for 2 to 3 WEEKS before letting anything touch it... but the can says 48 hours TOPS... is this guy wacky or is he onto something? Whatever the solution, it has to be done with spray cans, since my budget currently doesn't allow compressors, spray guns, etc...

HELP! I'm going nuts trying to figure out how to get a clear, solid coat over the paint! Any advice?

Thanks in advance

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I'm not the finishing guru around here, but a lot the clear finishes people use here are furniture-type stuff. For furniture, 72 hours is probably ok becauseyou're not laying it flat on a surface, putting it in a case, etc.

I know for a fact that Deft lacquer needs weeks, not hours or days, to fully cure. I haven't used rattlecan polys or enamels, but others here have. I'm sure we'll be hearing from them shortly. :D

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Manufacturors drying times are always pretty optimistic, and are usually based around how long a handyman has to leave his shelves before he can pick them up without leaving finger prints.

Most folks who use nitro will leave it weeks or months to cure before final levelling and buffing. Any sooner, and you'll get pores showing as the lacquer shrinks.

If the can says 48 hours, leave it for a few weeks. If the can says a week, leave it a month. You also want to be sure to leave it somewhere warm to dry - cold will retard the drying of most finishes.

Next time, finish it, then let it sit. Try leaving it on the towel - if it marks, let it sit some more. This will take less time and effort than constantly re-finishing with another product which will then need time to cure too!

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First Question: You say you're clear coating over paint. What exactly are you using?

The guys here will tell you that I'm old school and set in my ways but my experience has taught me that i prefer to use the same stuff all of the way through. Not a different type of clear caot.

You may be having problems 'cause you're using homeowner crap to try to get pro results.

I would suggest going to Guitar Re-Ranch, reading their tutorials and even buying some of their stuff.

I am real partial to nitrocellulose lacquer. I've used damn near everything at one time or another, but it's what I like.

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First Question: You say you're clear coating over paint. What exactly are you using?

The guys here will tell you that I'm old school and set in my ways but my experience has taught me that i prefer to use the same stuff all of the way through. Not a different type of clear caot.

You may be having problems 'cause you're using homeowner crap to try to get pro results.

I would suggest going to Guitar Re-Ranch, reading their tutorials and even buying some of their stuff.

I am real partial to nitrocellulose lacquer. I've used damn near everything at one time or another, but it's what I like.

The paint was Painters Choice spray that actually looks really good. The lacquer was painters choice, when that failed I tried Rustoleum Enamel, and when that didn't work out I tried polyurethane, can't remember the brand name right now... Keep in mind i've been sanding the "failed" layers off before I tried different stuff.

As for pro results, I wouldn't go that far. I don't expect it to look like a pro did it, I just want a reasonable looking clear coat to protect the paint. I'm all for using top of the line stuff, but money is an issue so I'm working with what I have.

Thanks for the advice

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You've just named two of the WORST choices for paint. I wouldn't paint a toy box with either of those. Re-ranch stuff isn't the cheepest, but it is quality stuff. I've also had a lot of success with automotive paint in rattle cans. Most hardware store type stuff is not going to give you a good finish.

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I think that a lot of your problems are related to

1)cheap paint and

2) using stuff that isn't quite compatible.

Just wait until the first time you even halfway whack your gitfiddle and a giant chip pops off 'caus of bonding problems..

If you don't want to go the Re-ranch route go to your local automotive paint supply store and get a couple of cans of touch up. It won't save you much over the Re-Ranch but a buck is a buck. At least price out the Re-Ranch, and figure what your time and wasted cheapo paint is worth.

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I think that a lot of your problems are related to

1)cheap paint and

2) using stuff that isn't quite compatible.

Just wait until the first time you even halfway whack your gitfiddle and a giant chip pops off 'caus of bonding problems..

If you don't want to go the Re-ranch route go to your local automotive paint supply store and get a couple of cans of touch up. It won't save you much over the Re-Ranch but a buck is a buck. At least price out the Re-Ranch, and figure what your time and wasted cheapo paint is worth.

Explanation please. WHAT isn't compatible with WHAT?! You keep saying not compatible but I don't know what you mean when you say that.

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Short answer, do your homework!!!! Do a little research before jumping in headfirst.

http://projectguitar.com/tut/tutorial5.htm

Longer answer, read the cans!! Stick with one brand/finish type. Even products from the same manufacturer may not be compatible with one another. Check what clear coats the manufacturer recomends with their color coat. this is all pretty basic stuff.

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Short answer, do your homework!!!! Do a little research before jumping in headfirst.

http://projectguitar.com/tut/tutorial5.htm

Longer answer, read the cans!! Stick with one brand/finish type. Even products from the same manufacturer may not be compatible with one another. Check what clear coats the manufacturer recomends with their color coat. this is all pretty basic stuff.

I've read through those and they didnt' answer the question I had, which is why I posted here. I think I've got my answer though, and I was just trying to find out a little more since you learn by doing and asking, or so I was always told.

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I'd think compatibility only revolves around using more than one kind of finish material. Its best to stick with only one. But in most instances you have to understand the nature of the beast. You can't just spray a guitar without thinking about environmental conditions before, during and after. Most of us learn by trial and error. Sure, someone can tell you that it won't work but we usually have to see it for ourselves and pay the consequences. :D

Here is a good example. I painted an SG copy I made with black laquer. After that cured I was ready to do the clearcoat in automotive laquer. I laid the guitar on my workbench in the backyard and then got side tracked by a phone call. I then sprayed the clear on the guitar only a half hour later. It was a hot and sunny day. Within 10 minutes most of the finish started bubbling up. Some of the bubbles were almost 1 cm in diameter and went right down to the wood! Anything black will absorb heat like crazy. There was so much stored heat in that guitar and the air was so hot and dry that it caused the clear to dry almost immediately. A skin formed on the surface while the underlying finish was still trying to gas off.

In your case you obviously did not wait long enough. You failed to give the finish the fingernail test (see if it dents easily). That would have told you right away that its too soon to polish. If you can still smell it then that means its still gassing off.

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I've used Dupli Color acrylic lacquer (Truck/SUV) for my lastest project. The product builds up easily and is easy to spray. Sanding is easy, so are repairs, due to the nature of the product (lacquer).

The only drawback with this product is that it takes forever to cure. I've been waiting 3 months for my guitar to cure but still, the finish is soft. I've heard that this product can take up to a year to fully cure, maybe more. I've decided to start using the guitar and I'll repolish it when it has cured a little more. I can see the lacquer is continuing to dry because it is shrinking and sinking into the pores of the wood (honduran mahogany). Its still very soft and fabric will leave an impression in the paint. The reason why I decied to use this product is that acrylic lacquer is supposed to be more durable and chip resistant than nitro lacquer.

I've used DEFT nitro lacquer on another project. The nitro doesn't build up as fast as dupli color acrylic lacquer. It chips more easily but dries faser and also cures faster. After 3 months, the guitar had cured to the point where it passed the fingernail test. I have noticed though that it has continued to dry/shrink because I can now see the finish sinking into the pores. I don't mind that though - I actually like the effect. This was done on a stained Korina body.

I'm not sure what i'll use on my next body. I'm seriously thinking of using the Krylon line of products. I've seen impressive results with the product.

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Compatible can means a bunch of things.

1) the base solvents don't like each other. Trying to coat mineral spirit based stain, like Minwax, with lacquer before all of the stain solvent has completely evaporated is an oil and water type incompatibility.

2) Sometimes even if they are basically the same the degree of "hotness" of the solvents may cause trouble. Example: shoot non-spray can Deft over nearly any other lacquer and it will crincle and bubble. It has drying retarders so that it can be brushed and thus acts funny over other lacquers.

3) Shoot lacquer over latex paint. It will usually crinkle right up and look like crap.

4) Some finishes simply won't bind to others.

I could go on for pages.

To get really good results you gotta bite the bullet and spend the clams.

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I've used Dupli Color acrylic lacquer (Truck/SUV) for my lastest project.  (snip)

The only drawback with this product is that it takes forever to cure. I've been waiting 3 months for my guitar to cure but still, the finish is soft. I've heard that this product

I'm finding this to be kind of strange...I'm using auto acrylic lacquer too...it seems good to go after about three WEEKS, and I wait another week or so.

Could it be that you didn't seal the mahogany properly?

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Not the duplicolor thing again, !!!!! :D

This stuff is best left for cars! And only for small repairs. I haved even painted bumpers with it with no problem, even fast cure and polish 2 days later...

(Disclaimer! This is my view on the subject! I ain't no chemistry major or scientist)

So whats the problem? After a lot of hair pulling and coffee cups I came to the conclusion that it is the material you are painting that doesn't like the paint! (idch the duplicolor you have overseas is not the same that we have here!)

When you paint metal, the paint is not only drying from evaporation but also the metal is thinner that a guitar body and there is some "heat" transfering from the bottom too. On a guitar, the wood stays cool. or at least at room temperature (except for the one of us that have been dumb enough to leave the bodies drying at direct sunlight).

Duplicolor is a great paint, but to build up the sheen that we want on our guitars it takes a lot of clear coats, and this stuff is not good for it. The main problem is that it flashes quick and you can spray more than the fair share of clear in a too close time. This will make the paint not dry evenlysince the thick layer will start curing on the top and closing the window for the bottom layers to evaporate propertly! I think that on this paint (duplicolor) you might benefit of painting a lot of very light single passes coats and no more than 2 a day, very far apart, like 6 hours. to give it enought time to dry before applying the next coats...

The main problem with the above method is that I don't know how good will the new coats will burn (or stick) to the previous ones... Since I use DEFT (nitro) I know that there is not problem because they burn thru very good, and I have been able to sand and polish the guitar in 2-3 days after the last coat is done... (But word to the wise! What Perry mentioned is true here! As the coats dries it will shrink a bit more showing the grain a little bit, so wait about a week or 2. one it shrinks totaly have a blast and level and polish.

Duplicolor base paints (at least the ones formulated for a clear top coat) will have no problem with nitro clear coats, as long as they are throughly dried. I did a few test with the blue bahamas and the mirage system and it turn out nice, on the mirage I will say that better than with the duplicolor clear over it!

That paint on your guitar will never fully cure, my last one with that problem, EVH inspired LP was painted with Duplicolor and it spent almost 6 months waiting to be sanded and polished! And all I painted was the top! Still now after almost a year later it is still shrinking and it looks awful to say the least (at least up close). And will be getting a redo pretty soon.

Good luck with what ever you do, but I recommend that you strip the whole thing again and get good paints. A water based base color or even the ones that duplicolor sells to be top coated and use DEFT as a top coat instead, a lot of people have had good experince with other paint but this is the only one that have done me good, so from here it's either spraying nitro with a gun or 2 part poly.

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