Jump to content

Recommended Posts

Posted

hi i read a few other posts on finishing. in one it said ploy is much more hazardous to your health then nitro. any idea why that is and is it really that bad im just doing some quick touich up work with spray can poly.

Adam

Posted

Spray can poly isn't the same thing as the poly you're referring to. The hazardous "poly" is actually a two part clear coat. It's dangerous because it has cyanoacrylates in it, which is also found in super glue :D. Cyanoacrylate is a carcinogen. Although I still recomend you use a respirator when spray what you've got.

peace,

russ

Posted

Spray can poly isn't the same thing as the poly you're referring to. The hazardous "poly" is actually a two part clear coat. It's dangerous because it has cyanoacrylates in it, which is also found in super glue :D. Cyanoacrylate is a carcinogen. Although I still recomend you use a respirator when spray what you've got.

peace,

russ

im looking to use krylon spray can poly and acyrlic poly, so that stuff is not more dangerous then nitro? Also is spray can poly suitable for touch up work on a prs( polyester base coat followed by an acyril urethane top coat) and a fender clapton strat ( satin polyurethane)? i have both acyrlic and regular poly in a spray can both by krylon.

Adam

Posted

The polies found on production models are not the same as what you have. They use the two part stuff. I know that for a fact because I read an article about how PRS uses an automotive grade clear from dupont. So I seriously doubt you'll have much luck touching up those finishes with what you've got. I can't tell you much about touch ups and repairs, that's really not my specialty...not that anything is.

Posted

When you say "touch up" what are you referring to? Dings? Chips? Large areas? Polyester and the Urethanes referred to here are finishes that do not combine with any other. I'm not sure how to describe it really, but I'll compare it to nitro. When nitro is applied to nitro will 'melt' a little into the surface of the previous layer. Poly and Urethane do not. They will only 'bond' with the surface if it is rough sanded. This makes spot repairs a little more difficult as it will not blend really, and surface repairs ahve the potential to just fall off.

I use a production polyester on my guitars. However, I have plans to use the same urethane product Fender applies to their American Strats this year as a proof of concept. Neither product 'melts' any layers underneath when the next is applied. Both of these are a mixture of 3 components, plus a thining agent if desired.

If your plan is to recoat that PRS then you should sand it well, especially in the really hard to get to places, using a fairly course grit paper. This is especially important because you don't want the new finish to flake off if the body gets bumped down the road some time. In my shop we use 180 grit between layers. I don't know what other readers think, but the thought of using household coatings on a PRS sorta makes my hair stand on end. Are you sure you can't just fill the the bad spots and buff it out again?

For dings and such use System 3, T-88 or other high strength epoxy. DO NOT USE HARDWARE STORE EPOXY AS IT DOES NOT HARDEN - EVER!! That means stuff from Home Depot, or Lowes, or wherever.

I think this is information overload, but I hope you find it usefull just the same.

-Doug

Posted

Possum, I've already made myself horse repeating this, so you get it one more time, then I give up:

**IF YOU ARE GOING TO DROP THAT MUCH COIN ON GUITARS, DROP SOME COIN ON GETTING THEM PROFFESIONALLY REPAIRED.** Those guitars are *not* appropriate test beds for learning finish touch up, and you are virtually guaranteed to make an expensive mess if you use them as such. Either learn to live with the dings, have a proffesional fix them, or sell the damn things and buy ones without dings.

Posted

Polyester has not got any cyanoacrylate in it. It is a 2-part which is cured off with a peroxide hardener. It is polyester monomer resin dissolved up in styrene, which is not good to drink.

Nitrocellulose is solvent-based and all solvent fumes are not exactly beneficial to health.

Acrylic spray (aerosol can stuff) is also resin in a solvent carrier (+ propellant) again breathing the fumes is never recommended. It is essentially a 1-part system.

Polyurethane is a different 2-part system and has typically an isocyanate hardener in it, not cyanoacrylate. Isocyanates are nasty but it only uses a tiny bit in it as a hardener to cure it off, so on the whole I would say there's not much more significant health risk using any of the popular finishes as long as common sense on ventilation is opbserved.

You have to be a bit careful when so many people just refer to 'Poly' coatings and they all may mean something different. As a generic term it is inaccurate and causes confusion.

Posted

hi is the factory poly on a prs and a fender neck safe to touch if there is a chip in it through to the wood in the area that is exsposed? or is it just bad for your health when you are spraying and sanding it?

ADAM

Posted

Dont forget that the dust from Polyester is very bad for your lungs. Always wear a mask when flatting it. The dust particles are large enough to sit on the inside of your lungs and cause damage.

Posted

Polyurethane is a different 2-part system and has typically an isocyanate hardener in it, not cyanoacrylate.

Potato, potato. Tomato, Tomato. My mistake, thanks for the correction. This is why I'm a mechanical engineering major and not a chemical engineering major :D .

Posted

You can use super glue if it's a minor ding, but you'll have to wet sand and buff the body again or it won't look right. It's really best, for you to refinish the guitar again, if you want it perfect. But then again, you have to be realistic with yourself. Do you have the right equipment and know how to pull off a better job, than if you'd have left a couple of dints and dings in the original finish? That's really the question you need to ask yourself.

Posted

It's hard to get superglue drop fills to look perfect. It really has to be leveled with a gentle touch and a sanding block(wet sanding, of course), or else you'll have a very noticeable bump in the finish.

Posted

CA is a decent for those little drop fills, but epoxy is harder in the end and will stand up should the body ever be wiped with a solvent that reacts with CA. No matter what you opt for, it will need to be carefully leveled and buffed.

-Doug

Posted (edited)

http://www.resene.co.nz/comn/safety/lacquers.htm

The stuff in rattlecans eg. Minwax clearcoats etc. are part of the first group and the industrial type of poly paint (2-part polyurethane resin) is in group 3. A little research goes a long way. A search on "isocyanates" will give you TONS of safety info regarding exposure to these nasty chemicals. This type of paint is used exclusively in the high end yacht building industry. When they start spraying I'm out the door. :D

Once the paint is cured, and I say "cured" not just "dried", then all the free isocyanates have reacted and are rendered inert. But in the mean time the poly still has potential to do harm. I wouldn't bring the guitar into my home for at least 2 weeks, by then most of the isocyanates have reacted.

Edited by Southpa
Posted

It's hard to get superglue drop fills to look perfect. It really has to be leveled with a gentle touch and a sanding block(wet sanding, of course), or else you'll have a very noticeable bump in the finish.

Agreed.

CA is a decent for those little drop fills, but epoxy is harder in the end and will stand up should the body ever be wiped with a solvent that reacts with CA. No matter what you opt for, it will need to be carefully leveled and buffed.

-Doug

Yes, epoxy is probably a better choice, but I've personally used CA glue before and it worked good. Just wanted to give him another option. I'm with you though, to do an even halfway decent job, your going to have to be very careful with how you do it. I personally don't think you should practice on this guitar though!!!

Posted

Personally, I'm devoutly against repairing a guitar's "character." How would you like it if someone took away your scars? Then you'd lose all of your cool conversation starters and affirmations of manliness.

Posted

Personally, I'm devoutly against repairing a guitar's "character." How would you like it if someone took away your scars? Then you'd lose all of your cool conversation starters and affirmations of manliness.

so after reading what u all said my guitars are perfectly fine health wise with a few dent that chipped the wood and poses no threat to my health with everyday contact, correct? since poly sounds like some real fun to play with im just gonna leave both guitars alone, or possible just get a new neck for the strat. i can deal with the chip on the prs it doesnt effect the playability at all but the finish wear on the strat neck is kinda annoying though.

Adam

Posted

Yes, everything is fine; have you ever heard of this little known guy called Stevie Ray Vaughn? His guitars had a few( :D ) scratches and dents, but they sounded just fine :D .Perhaps the strat neck would feel better with a light sanding from with high grit paper to smooth it out a bit. I take it you have chipped paint on the neck?

Posted

Yes, everything is fine; have you ever heard of this little known guy called Stevie Ray Vaughn? His guitars had a few( :D ) scratches and dents, but they sounded just fine :D .Perhaps the strat neck would feel better with a light sanding from with high grit paper to smooth it out a bit. I take it you have chipped paint on the neck?

looks is what im concerned about. i jusat really wanna know if touching the damaged area is hazardous health wise?

Adam

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...