Does this approach make sense?

The Achilles' Heel of Luthiery
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jarone
Posts: 4
Joined: Mon May 10, 2021 12:36 am

Does this approach make sense?

Post by jarone »

Hi there!
I've used this website several times as a resource during my build process, thank you for the wisdom. Specifically Blues Creek Guitars, I've watched MANY of your videos, including ones on neck set and finishing. This is my first attempt at building a guitar and it has gone rather well as far as I can grade. I do have some background in basic furniture building and that proved invaluable. I'm nearing the end of the build phase, and had always hoped that I could find someone local to do the finish work for me. Unfortunately, it has proven an extremely difficult process, and have resigned to doing it myself. I've done some basic spray work in the past, so it's not something completely foreign to me. I've outlined below my intended approach based on my research and I would like some generic feedback and have asked some questions below. The two biggest questions I have
1) Is this sealer, filler, and lacquer compatible with each other?
2) when NOT to sand between coats, when to sand between coats and with what grit.

Details: I am building a Martin Dreadnought from a kit. It has rosewood sides/back, spruce top, mahogany neck, Ebony fingerboard, plastic bindings. I am not going thing for anything out of the ordinary, and would just like to achieve a nitro finish typical for this type of guitar.

Plan:
Prep work:
  • Sand everything to 220.
  • ? Do Bindings also get 220?
  • What do you clean the surfaces with? Denatured alcohol or tack cloth?
Sealer: Filler
  • First 2 coats of AquaCoat
    at least 1 coat with grain, 1 coat against, work in small zones. Scuff sand between coats always with block.
  • 2 coats of sealer, level sand.
  • ? what grit?
  • ? Time between coats?
  • ? what am I using to clean between coats? Air? Denatured?
Finish:
  • Plan on finishing in my garage using Mowhak Lacquer
  • Warm the cans in warm water for 15 minutes, warm the shop.
  • Spray 4 coats a day, 1 hour a part, for 3 days.
  • Final sand/buff...I'll be honest I haven't quite researched this yet.
Thanks for reading, any feedback welcome!
Josh
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tippie53
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Re: Does this approach make sense?

Post by tippie53 »

Sand everything to 220.
I do 180 but don't go finer than 220

? Do Bindings also get 220?
yes

What do you clean the surfaces with? Denatured alcohol or tack cloth?
I am a fan of naphtha
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
jarone
Posts: 4
Joined: Mon May 10, 2021 12:36 am

Re: Does this approach make sense?

Post by jarone »

Thanks for the feedback above, John. I’ve gotten through the seal>pore fill phase and feeling pretty good about the progress. When I went to put seal coats on top of the pore fill, I noticed that certain areas of the rosewood were weeping along the grain. When the seal coat dries, it does not feel wet/tacky or different in any way, but when inspecting under the light, it definitely looks different. I’ve made certain to spray only on days where humidity is better than 70% and at least 65 degrees out. I’ve also heated up the rattle cants in warm water and given them a thorough shake. During the build process I made sure to keep these wood clean and didn’t really soak it in water, save for occasionally wiping it off with a wet rag to clean the dust off of it.

Any thoughts on what this could be and possible remedies? Thanks in advance,
Josh
tippie53
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Re: Does this approach make sense?

Post by tippie53 »

things should look different when the finish starts building. if not sand back and start over post some pics if you can
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
jarone
Posts: 4
Joined: Mon May 10, 2021 12:36 am

Re: Does this approach make sense?

Post by jarone »

Apologies, I thought I had attached images.

When looking at the finish under magnification loups, you can see that the finish is reacting with something in this location. My gut is telling me that the wood is leaching oils at these spots, maybe encouraged once the sealer gets on top of it. As you've mentioned, one of the things I've contemplated is sanding it back down to raw wood and starting the process over but I'm mostly certain that I'll get the same results as I've done this already after the seal coat>Pore fill phase (I noticed it on the first seal coats). At this time I sanded down to bare wood and the spots were gone.

Aesthetically I don't mind it...wood is just being wood. I just want to make sure that the lacquer will lay on top of this and polish well and more importantly, that it won't cause trouble down the road.

For what it's worth, I used Aqua Coat pore filler and mohawk ez-vinyl sealer.
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tippie53
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Re: Does this approach make sense?

Post by tippie53 »

try to spot fill then reseal I don't think you got that area filled or was that area a bit rough? Under finish that will go away
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
jarone
Posts: 4
Joined: Mon May 10, 2021 12:36 am

Re: Does this approach make sense?

Post by jarone »

Just so I'm clear:
Sand down to bare wood, re-fill those areas with Aqua Coat really well, re-seal?

Should I consider CA fill in these areas? (if so, is it compatible with the aqua coat?)
Josh
Diane Kauffmds
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Re: Does this approach make sense?

Post by Diane Kauffmds »

I'd sand it down. Make sure you use a block and not your hand. Also, sand the whole area and not just that small area. If you use your hand and/or just concentrate on that spot, you'll have a low spot that's visible and can be felt. So just use a block, sand with the grain, and sand a good area around it too, if not almost the majority of the bout. You'll be fine.
tippie53
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Re: Does this approach make sense?

Post by tippie53 »

I don't think you need to sand this down but you do need to refill the area and reseal the pics are tough but I have seen this before
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
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