MIMF

hey dudes and dudettes. Its been a long time, stuck on a problems not sure what to do. asking for some help.

I have a customer who wants an aged gold top. So I built the single cut carved top.

Here has been my steps:

Sanded maple top down to 600
applied Stew Mac White Prime (3 light coats)
then stewmac antique bronze let it site for a few days (4 coats)
Apply vintage Lacquer also from Stew Mac. (4 coats)
Let it dry in hot box and UV light kit for 4 days.
Start cycle of heating and cooling to get checks in freezer. nothing happening after 4 cycles.
Move to Dryer and desk cleaner upside down. (spray light and heavy combinations)
Lacquer and paint actually crack, cracks pull the gold away from the top. happened in a few spots.

This is the 2nd time I have done this with the same cracking. Its like the gold is not sticking to the primer.

I am frustrated, customer is frustrated.

Why is the paint chipping? doesn't make any sense to me. I have done this with other guitars and have had the desired results. I don't know what to do?

I feel your pain!...I do a lot of relic guitar finishes and it's always quite "hit and miss", some go really well and others just don't behave. I don't know what the Stewmac lacquer is but I always use nitro cellulose and a make that is low in plasticisers. I don't like using the pipe freeze/spray cooling as it is to violent and tends to produce a pattern that's more like the craze cracks on old pottery. Like you I put the guitar in a freezer then warm it gently afterwards although the paint finish has to be at least 3 months old, nowadays I use a number of techniques from scribing the checking lines and freezing and some other techniques..Here's a picture of a goldtop I did the other day that I was really pleased with although it did take a long time to do but other people have said that they can't tell it from a genuine one so that was very pleasing.


As for the adhesion problem you're having it sounds like the undercoat and gold are not completely compatible, the trouble is with a goldtop is that the gold can't really be sanded afterwards so the undercoat has to be perfect and not pretty smooth so there isn't much mechanical bonding.

My instinct is you are rushing things. Applying the nitro lacquer over the vinyl sealer is fine, but I would let the final finish cure for two to three weeks, then wet sand and buff as normal, and then go for the relic checking. I don't know if four days in a hot box is a replacement for two to three weeks of cure time. And you don't mention any buffing stage for gloss. I think checking depends on a quite hard and thin coat, and it sounds like yours hasn't cured yet. Also not sure why you wait four days before spraying the clear. Stew-Mac seems to recommend just going with their normal 2 - 3 coats a day until done. But I try very hard to avoid checking, so I'm probably wrong...

Is the Stew Mac white prime vinyl sealer? If so I would skip it. Vinyl sealer doesn’t burn together with nitro. Test it out on scrap first.