GMC finishing

Moridin · #1 08-17-2006, 01:00 AM

Hello! This is my first post here...

I bought a GMC body from a guy I know. I think it's swirled by Darren Johansen. But it is not finished. The painting is rough (it's got like bubbles here and there :/). How do I finish it? Is it possible to sand it, to make the coat smooth? And then polyurethane clear coat (another guy I know could make it for... a cup of coffee). Or does the swirl go away if I sand it?

TAorama · #2 08-17-2006, 01:16 AM

I doubt if you'd want to sand it. It would probably make pretty ugly marks in the swirled paint. If there are bubbles that really stand up above the rest of the paint, you might try to knock them down with a razor blade - very carefully so as not to damage the surrounding paint. Clearcoat the body until it's relatively smooth/even, then wet-sand and polish the clear.

Moridin · #3 08-17-2006, 01:23 AM

Are you sure, that even grade 2000 sandpaper would damage the swirl?

**GilkyBear** · #4 08-17-2006, 01:38 AM

find (users) Tubarao or SCS on here and ask them, they do swirls...

Jaden · #5 08-17-2006, 08:37 AM

also serratus will be able to help

Serratus · #6 08-17-2006, 10:06 AM

PM replied to :-)
As I said in the PM, I would think that Jeremy at LGM would be the best person to ask for advice, as he's cleared Darrens swirls in the past.
Cheers,
Rich

Moridin · #7 08-17-2006, 10:22 AM

Ok, this guy who said it was painted by Darren was wrong... I'll just let this car painter do it. Case closed

But there's still a run in the paint, any way to remove it?

Serratus · #8 08-17-2006, 11:41 AM

Well, I would let this guy have a look at it - if he's done alot of spraying then hopefully he'll know what he's talking about.
I have seen swirls with runs and bubbles (bubbles actually usually happen somewhere on the body, although the top usually just comes off leaving a white circle). I still would try to avoid sanding it if you can, unless you can be accurate enough to just sand the run (depends how big it is). Or use a knife to carefully cut the bulk of the run away (again, depends on the size and depth of the run), as TAorama said.
One of the problems you have, as I see it, is that if you don't know who swirled it then you don't know what type of paint it is, so you don't know what will cover it or how thick it is.
I don't have much experience with polyurethane clear - does anyone else know whether it will cover most other paint types?

Moridin · #9 08-17-2006, 11:45 AM

I heard Ibanez uses polyurethane... But he can try it in the trem or pickup cavity first. It was painted by Chris Castillo.

PatrickSimsCustomShopUSA · #10 08-17-2006, 03:17 PM

You can put anything over polyurethane since polyurethane is catalyzed. Urethane, polyester, etc will all work fine, just need to make sure its sanded REALLY good 1st. I would actually smoothen the swirl out with sealer, since sealer is clear, and higher build. Sealer is made for filling.....clear coat really isn't.....although it will eventually with enough coats. I would seal it and block it and continue that process til its smooth, then once its smooth like you want it I would clear it. Thats really the right way to do it, and the best, not to mention it would be alot faster too since the sealer is much higher build.....AND it would be cheaper b/c sealer generally costs quite a bit less than clear....unless your using REALLY cheap clear.

So by going at it that route you would A) Save time B) Save money and C) Have a harder finish and more durable finish than if you had done all the filling with Clear Coat.

Clear on top of clear, on top of clear, on top of clear will actually begin to A) Yellow B) Crack easier C) Chip easier

I don't know what kind of sealer this guy you know uses, but as a general rule sealer is MUCH harder than clear coat (Granted its a catalyzed sealer). My sealer is hard as a rock when it dries.....you literally can't break it into with your hands no matter how hard you try. I was demonstrating it to a customer the other day and it actually cut my hand where I was trying so hard to snap it into.....the piece of sealer was about 1/16" thick, which isn't really that thick considering how strong it is.

Clear coat on the other hand, regardless of how thick it is, will snap right into with little to no effort. Now I know your guitar isn't going to be flexing, but my point is a HARDER finish is a more DURABLE finish, and a HARDER finish will last ALOT longer, and a HARDER finish won't soak in and sink in like a softer one will. The last thing you want to do is get the swirl filled and smoothened out with clear, buff it and it look like glass.....then 2-3 months down the road you can begin to see some ripples, lines, and waves where there swirls are at b/c the clear coat has began to totally cure and soak in and withdrawl a little bit, hence showing you all the low spots you tried to fill with the clear. Now it won't do it bad, but it will do it some.

So tell your buddy to SEAL it to FILL IT, and CLEAR it to GLOSS IT.

Moridin · #11 08-17-2006, 04:57 PM

This buddy talked about some insulating material that should be put under polyurethane (the paint would melt/boil otherwise)... is that sealer (my English is bad in these things

)? And said this material would crack the clear coat, if exposed to sunlight for a while.

PatrickSimsCustomShopUSA · #12 08-17-2006, 05:11 PM

I honestly have no clue what he's talking about, and I like to consider myself pretty knowledgeable about paint. Maybe its your buddy who doesn't know what he's talking about......(no disrespect intended, just want to throw out some possibilities that you may want to consider.....you have a very nice swirl and I wouldn't want just ANYBODY messing with it, cuz they could potentially ruin it)

I'll tell you this FOR A FACT, you can put ANY clear coat over polyurethane and it WILL not cause any problems as long as the paint job thats on there now has been on there for over 2-3 days.

NOTHING is going to boil/melt a catalyzed clear off except a heat gun, or maybe some SERIOUS Industrial strength paint stripper......period. Maybe you should send it to somebody who paints guitars, and ideally has actually painted some swirls before and has experience with them..........I can tell you from my experience if you start experimenting with paints, and painters who are not REAL SURE about how exactly to do something its just a recipe for disaster and 99.999% of the time you WILL have problems.

Serratus · #13 08-17-2006, 06:06 PM

Maybe I'm missing something, but you don't actually know that the swirl is poly do you (you don't say that it is)? SCS, you're saying that you can put anything over poly but it's the clear that Moridin is saying will be poly, not the swirl, or have I got that wrong? It may well be poly but you want to make sure if you can, before you go assuming that it is.

PatrickSimsCustomShopUSA · #14 08-17-2006, 06:08 PM

He sent me a PM yesterday and told me, if I understood him correctly, that it had a Poly clear on it right now.....but that it was just rough and wanted to re-clear it. Basically its simple.....Take an area like the Tremelo cavity, see if the clear will wipe off with lacquer thinner........ if it WIPES OFF then it has some kind of Nitrocellulose or Lacquer on it, if it DON'T wipe off your pretty much safe to put anything over it. Personally I would reclear it with Urethane before I would use Polyurethane, nothing wrong with Polyurethane I just think Urethane is better, nicer looking, easier to work with and more user friendly, buffs easier, etc etc But everybodys different I suppose.

Moridin · #15 08-18-2006, 02:19 AM

Hmm. Ok I could have been confusing

My English really isn't that good. The paint WIPES OFF with thinner, that's the problem :/ Sorry if I confused you.

I think he said the paint could be alchyd(? Alkydy in Finnish...)-based.

Those guys know what they're doing, they just haven't done swirls. He said the monkeygrip is not a problem, he won't get runs. www.faw.fi