Blister in the sun - what’s next?

[DarrenK]

Long time lurker. I have learned so much on this forum, thank you for sharing your knowledge.

See second picture for why you don’t want to let your guitar dry in direct sunlight. I know I read that here, I just didn’t factor in the sun doing down and moving in the garage.

Now, how do I fix this? It’s Duplicolor over shellac. I can also see the grain in some places. Do I sand down and start over? Should I sand the bubbles off, try to drop fill and then do the Duplicolor again? Something else?

I was considering doing a relic on this anyway, and since this is mostly the back, not sure it needs to be perfect.

TIA

 

[Telekarster]

First welcome! Second - Ouch. I don't know who/where you would've been advised to put it in the sun to dry, but that's not something I don't think most of us would've advised. Bad advice IMO. Anyway, I think what you might be able to do is to sand and feather down the blistered areas and respray. This is what I would do anyway. Good luck man!!!

 

[eallen]

Being a metalic it is quite hard to touch up without noticing it. Best scenario, block sanding the area of the spots smooth to avoid leaving any low areas. Recoat the entire body with color before going to clear. Otherwise it is sand it all off and start over.

 

[KokoTele]

If you see grain in some places, I'd sand/strip the duplicolor off, fill that grain better, and then reshoot the duplicolor.

Remember that shortcuts in finishing usually take longer.

 

[DarrenK]

First welcome! Second - Ouch. I don't know who/where you would've been advised to put it in the sun to dry, but that's not something I don't think most of us would've advised. Bad advice IMO. Anyway, I think what you might be able to do is to sand and feather down the blistered areas and respray. This is what I would do anyway. Good luck man!!!

Apologies for being unclear. I meant to say I know that I read NOT to allow direct sunlight. I tried to avoid that, but goofed as the sun went down, indirect became direct.

 

[oldunc]

By the way- finishing rags left out in the sun to dry- or even a hot day- really can combust spontaneously.

There's ALWAYS a song;

 

[Si G X]

Nothing, it was their only good song.

 

[Nicko_Lps]

Long time lurker. I have learned so much on this forum, thank you for sharing your knowledge.

See second picture for why you don’t want to let your guitar dry in direct sunlight. I know I read that here, I just didn’t factor in the sun doing down and moving in the garage.

Now, how do I fix this? It’s Duplicolor over shellac. I can also see the grain in some places. Do I sand down and start over? Should I sand the bubbles off, try to drop fill and then do the Duplicolor again? Something else?

I was considering doing a relic on this anyway, and since this is mostly the back, not sure it needs to be perfect.

TIA

After years working with wood and finishing my own works... I strongly suggest you to remove everything from the back and re-finish it.
When you are working to cover up a mistake, you end up working alot more and doing a worse job.

Now that applies to normal situations.. You are planning to relic it so you could possibly cover it

 

[Peegoo]

If you have an otherwise nice flat surface, all the hard work is done for you. Carefully block sand the blistered area and then scuff sand the entire body. Shoot a coat of two of sandable primer. Sand that smooth and then shoot color.

If that were my project I'd go that direction instead of stripping everything off and going back to bare wood. Why re-do the surface prep if it's already done? The whole "thin finishes are better than thick finishes" argument has far far less impact on a guitar's tone than the wood, the neck, the frets, the hardware, and the phases of the moon.

 

[Buckocaster51]

Never try to do body work with the color coat.

 

[DarrenK]

If you have an otherwise nice flat surface, all the hard work is done for you. Carefully block sand the blistered area and then scuff sand the entire body. Shoot a coat of two of sandable primer. Sand that smooth and then shoot color.

If that were my project I'd go that direction instead of stripping everything off and going back to bare wood. Why re-do the surface prep if it's already done? The whole "thin finishes are better than thick finishes" argument has far far less impact on a guitar's tone than the wood, the neck, the frets, the hardware, and the phases of the moon.

So you rather than sand everything off and start over, sand to smooth rough spots/bubbles, scuff the rest, then put primer over the remaining lacquer? Any recommended sandable primer?

 

[Peegoo]

So you rather than sand everything off and start over, sand to smooth rough spots/bubbles, scuff the rest, then put primer over the remaining lacquer? Any recommended sandable primer?

Preferably one that is made by and compatible with the color topcoat supplier.

 

[RodeoTex]

I'd block sand it until everything was at least flat, theme start back with a couple coats of sanding sealer, or vinyl sealer.
Block sand that and then put on a light coat of a colored primer.
That will a show if you've got the wood grain buried. If not, block sand again, another coat or two of sanding sealer, block sand again, primer again.
You can certainly tell when you're ready for color.
I've had guitars bubble up like that. Heartbreaking.

 

[oldunc]

Nothing, it was their only good song.

Well, haven't seen Gordon Gano on anyone's "favorite singer" lists, but I seem to remember that I kind of liked the album.

 

[Si G X]

Well, haven't seen Gordon Gano on anyone's "favorite singer" lists, but I seem to remember that I kind of liked the album.

I was just kidding....










... I don't even like 'Blister in the sun' really.

 

[DarrenK]

An update, and more help requested. I decided that I wanted to strip the body and start over. There were enough issues with the bubbles and the grain that I decided to just start over. I figured before I strip everything off, I'd try a few sample racing stripes to see if I liked the width/placement. Well, as I was repositioning the masking tape, it ripped the color coats right off. I tried both the blue painters tape and the regular old tan masking tape, and they both pulled off the duplicolor equally well. This made me realize that I probably need a better adhesion between the duplicolor and the shellac.

I went back to two auto parts stores, and got another can of the perfect match, and tried to find duplicolor primer. Neither store had duplicolor, only several different types/colors of Rustoleum.

Trying to rebuild my finish schedule:

1. Sand to 320
2. seal with Zinsser spray shellac (I could not find vinyl sealer locally)
3. grain fill with 45 joint compound. sand to 320. repeat until smooth (3-4X)
4. Shellac again
5. Primer - I bought Rustoleum 2 in 1 Sandable Filler primer (to fill in any other grain). Sand to 400
6. Duplicolor Perfect Match Magnetic Gray Metallic (my substitute for Charcoal Frost Metallic)
7. Wait X hours/days to dry
8. Mask with Frogtape and 3M pinstripe tape
9. Spray one coat of Duplicolor MGM to seep into any tape gaps
10. Spray Duplicolor Reflex Silver
11. wait Y hours/days to dry
12. Spray Minwax Gloss Lacquer
13. maybe sand, hopefully just buff.

Anyone that has used Duplicolor successfully on an open grain wood (ash), please chime in.
What primer did you use/like?
Have you ever masked to spray racing stripes?
How long do I need to wait for the paint to dry before masking for the stripes?
How long should I let the color coat dry before spraying w/ the gloss lacquer?
Any other stupid mistakes you see above?

 

[stratisfied]

This will grain fill, prime and improve adhesion. Forget about shellac, it's a legacy clear sealer that is not relevant to painting unless you're spot-sealing knots in wood before priming. Ever hear of an auto paint shop using shellac as a primer under basecoat/clearcoat paint systems? Me neither.

 

[Winky]

What's the shellac for? If you're going to use an automotive system, start at the bare wood, then a coat of something that primes the wood for the paint system you're using. They don't spray cars with shellac.

 

[KokoTele]

An update, and more help requested. I decided that I wanted to strip the body and start over. There were enough issues with the bubbles and the grain that I decided to just start over. I figured before I strip everything off, I'd try a few sample racing stripes to see if I liked the width/placement. Well, as I was repositioning the masking tape, it ripped the color coats right off. I tried both the blue painters tape and the regular old tan masking tape, and they both pulled off the duplicolor equally well. This made me realize that I probably need a better adhesion between the duplicolor and the shellac.

View attachment 1003373

I went back to two auto parts stores, and got another can of the perfect match, and tried to find duplicolor primer. Neither store had duplicolor, only several different types/colors of Rustoleum.

Trying to rebuild my finish schedule:

1. Sand to 320
2. seal with Zinsser spray shellac (I could not find vinyl sealer locally)
3. grain fill with 45 joint compound. sand to 320. repeat until smooth (3-4X)
4. Shellac again
5. Primer - I bought Rustoleum 2 in 1 Sandable Filler primer (to fill in any other grain). Sand to 400
6. Duplicolor Perfect Match Magnetic Gray Metallic (my substitute for Charcoal Frost Metallic)
7. Wait X hours/days to dry
8. Mask with Frogtape and 3M pinstripe tape
9. Spray one coat of Duplicolor MGM to seep into any tape gaps
10. Spray Duplicolor Reflex Silver
11. wait Y hours/days to dry
12. Spray Minwax Gloss Lacquer
13. maybe sand, hopefully just buff.

Anyone that has used Duplicolor successfully on an open grain wood (ash), please chime in.
What primer did you use/like?
Have you ever masked to spray racing stripes?
How long do I need to wait for the paint to dry before masking for the stripes?
How long should I let the color coat dry before spraying w/ the gloss lacquer?
Any other stupid mistakes you see above?

Forgive me for my frankness here, but you're mixing products and processes without the experience or skill to evaluate how well they'll work. That's a recipe for problems. Stick with a single family of products and use the manufacturer's instructions for your finishing schedule. If you can't find all the stuff you need locally, order it. You'll waste more time redoing work than waiting for the product to come by UPS.

Since Duplicolor makes the color coats you want, use their primer and their clear coats.

At this point, I'm not sure the shellac will aid the grain filling steps at all. Normally it's only needed to keep your grain filler from staining the wood and getting in the fine pores between the grain lines. That's not a concern for you since you'll be spraying opaque color coats. Just keep redoing the grain filler process until the pore are gone, then spray your first primer coats.

When you sand your primer coats, you'll find flaws in your grain filling. Either apply more filler now, or spray and sand primer coats until you stop finding pores to fill. A good way to do that is to block sand and then wipe with a paper towel that's damp with a compatible solvent, like naptha. If there are any open pores to fill, you'll see little puddles for a few seconds before it evaporates. If they're very small, sometimes it's more effective to spray some of your primer into a cup and apply it to those spots with a little brush.

After your primer coat looks perfect, then proceed to color.

Even if you use the frog tape, stick it to a counter or your shirt or something before applying to the guitar. That will remove a lot of its stickiness and help prevent it from pulling off your color coats. Spray the stripes, let it dry just long enough to tack up, then remove the tape. Pull up and *towards* the wet paint you just sprayed. That will keep it from pulling little tendrils of wet paint toward your sparkle coats.


And go easy on yourself. You've chosen a scheme that requires some advanced skills to execute properly, so you have a steep learning curve.

 

[DarrenK]

Thanks, KokoTele for the frankness. I know I don't have the experience, so trying to get advice before I waste time and money redoing everything multiple times.

In good news, I was able to find Duplicolor primer locally. Not filler primer, so that might require more work after spraying, but so be it. Also, thanks for the feedback on shellac/sealer. Unfortunately, I already put the first coat of shellac on right after posting. Here's my updated workflow:

1. Sand to 320 - done
2. seal with Zinsser spray shellac (I could not find vinyl sealer locally) - done
3. grain fill with 45 joint compound. sand to 320. repeat until smooth (3-4X) - started
4. skipping the shellac
5. Primer - Dupli-Color DAP1689 White General Purpose Sandable Primer. Sand to 400
6. Duplicolor Perfect Match Magnetic Gray Metallic (my substitute for Charcoal Frost Metallic)
7. Wait X hours/days to dry - how long to wait before masking? overnight enough, or should I wait a few days?
8. Mask with Frogtape and 3M pinstripe tape (tape onto shirt before putting on guitar)
9. Spray one coat of Duplicolor MGM to seep into any tape gaps
10. Spray Duplicolor Reflex Silver - remove tape once tacky
11. wait Y hours/days to dry
12. Spray Minwax Gloss Lacquer
13. maybe sand, hopefully just buff.

I'm going to stick with the Minwax Gloss Lacquer vs the Duplicolor clear. Nearly every mention of the duplicolor clear on this site is negative. At least the negative reviews have far outweighed the positive. I have seen several guitars posted w/ the Minwax over the duplicolor, so I'm confident in that compatibility.

Pull up and *towards* the wet paint you just sprayed. That will keep it from pulling little tendrils of wet paint toward your sparkle coats.

Thank you for this tip. I will easily do it on the outside strips. On the inner strip(s), I'll just have to pull straight up though, right?