Grain Tearout - Ouch

The Achilles' Heel of Luthiery
twenty2late
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Joined: Sat May 28, 2016 8:48 am
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Grain Tearout - Ouch

Post by twenty2late »

I'm about to start French polishing this top, and I have 2 areas like this. Not sure if it's from scraping, sanding, tape, or something else. Can this be fixed before polishing? They look way too deep to sand. Maybe some thin CA? Something else? Thanks.

V/R
Ken
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Diane Kauffmds
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Re: Grain Tearout - Ouch

Post by Diane Kauffmds »

Never use CA glue on spruce. It'll eventually discolor the wood.

I've been able to sand out minor tear out. You'll want to sand the hole top so you don't end up with a dip in the top.

If this isnt possible, you can minimize it with some sanding, then drop finish some shellac will fill those areas the rest of the way. Allow some shellac to thicken, so it's almost a soft gel, and roll it into those spots. I've done it at the end of French polishing, but expect it to take forever and an eternity to harden.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
twenty2late
Posts: 81
Joined: Sat May 28, 2016 8:48 am
Location: Savannah, GA

Re: Grain Tearout - Ouch

Post by twenty2late »

Doing some research on here...it looks like clear burn in stick will help too? I actually bought some of that a while ago, based on a Brian Howard video. I just couldn't figure out how to use it right. Apparently, I have some learning to do tonight!!!
Diane Kauffmds
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Re: Grain Tearout - Ouch

Post by Diane Kauffmds »

I didn't even think about a clear burn in stick. Yes, that should work.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
MaineGeezer
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Re: Grain Tearout - Ouch

Post by MaineGeezer »

I suspect your best bet would be the shellac fill.
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tippie53
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Re: Grain Tearout - Ouch

Post by tippie53 »

seen this many times
most likely tear up from tape. I bet you have room to sand it isn't as bad as it looks the finish makes it look that way
jh
John Hall
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twenty2late
Posts: 81
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Re: Grain Tearout - Ouch

Post by twenty2late »

So...a little clear lacquer burn in, resanded the entire top, and the tear out is gone! Already have 2 coats of FP on it, and the areas are invisible!

John, I saw in a previous post that it took you about 14 guitars before you learned how to finish them. What were you using on the early guitars? I can't quite swallow the cost of out sourcing a nitro finish. But, at the same time, FP is killing my arm and wrist!

V/R
Ken
Diane Kauffmds
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Re: Grain Tearout - Ouch

Post by Diane Kauffmds »

twenty2late wrote:So...a little clear lacquer burn in, resanded ppl] the entire top, and the tear out is gone! Already have 2 coats of FP on it, and the areas are invisible!

John, I saw in a previous post that it took you about 14 guitars before you learned how to finish them. What were you using on the early guitars? I can't quite swallow the cost of out sourcing a nitro finish. But, at the same time, FP is killing my arm and wrist!

V/R
Ken
I know you asked John the question, so please excuse my intrusion. I might be able to help. I certainly understand your pain.

French polishing is great upper body workout, that's for sure. I don't know if you've established a routine, but a routine helps a lot. I have a plate in my neck and lower back. I also had both hands and rotator cuff surgery a year ago. I do 2 or 3 sessions per day. In the build-up phase, I put 2 or 3 coats on per session.

But, when I did my first fp, I had problems with shoulder and hand pain. I cut down to 1 to 2 sessions per day, and only 1 or 2 coats per session, until I built up stamina.

I also spray nitro. I have a compressor and I use an Ingersoll spray gun Mod. 200G. I get the nitro from stewmac. They also have aerosol cans of nitro, and I've heard that you can get a good result from using the canned nitro. You need to wear a face mask rated for filtering VOC's when you use it, and you need really good ventilation.

Others on the forum have used shellac as a base coat, to bring out wood figure, followed by True-Oil. The shellac needs to be set before switching to any other media.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
twenty2late
Posts: 81
Joined: Sat May 28, 2016 8:48 am
Location: Savannah, GA

Re: Grain Tearout - Ouch

Post by twenty2late »

Thanks Diane! To be honest...I'm terrified to do my own spraying! I have to operate in my garage and my water heater (with pilot) sits behind me. I'm sure if I had a safe area, and built a suitable spray booth that I could easily learn to spray.

I actually find most of the pain from FP to be in my hand and wrist. My routine is about 2-3 coats a day focusing on the backs and sides or just on the top, so it's not a lot of work, but my hand cramps up from holding the pad and pushing the shellac onto the wood.

I've also tried tru-oil on 2 of my builds....but I didn't put down a shellac base coat. That actually sounds like a great idea. I don't like the finish of tru-oil alone, but I absolutely love how the shellac makes the wood "pop"!

I'm retiring from the Air Force in 2018, and the wife told me that wherever we settle down that I can build a stand alone workshop. That will help with the safety of spraying, but I imagine I will legally have to discuss it with my insurance, which would probably be almost as expensive as out-sourcing?

V/R
Ken
Diane Kauffmds
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Re: Grain Tearout - Ouch

Post by Diane Kauffmds »

twenty2late wrote:Thanks Diane! To be honest...I'm terrified to do my own spraying! I have to operate in my garage and my water heater (with pilot) sits behind me. I'm sure if I had a safe area, and built a suitable spray booth that I could easily learn to spray.

I actually find most of the pain from FP to be in my hand and wrist. My routine is about 2-3 coats a day focusing on the backs and sides or just on the top, so it's not a lot of work, but my hand cramps up from holding the pad and pushing the shellac onto the wood.

I've also tried tru-oil on 2 of my builds....but I didn't put down a shellac base coat. That actually sounds like a great idea. I don't like the finish of tru-oil alone, but I absolutely love how the shellac makes the wood "pop"!

I'm retiring from the Air Force in 2018, and the wife told me that wherever we settle down that I can build a stand alone workshop. That will help with the safety of spraying, but I imagine I will legally have to discuss it with my insurance, which would probably be almost as expensive as out-sourcing?

V/R
Ken
I'm an Air Force Vet too, well before your time I'm sure.

You don't want to spray nitro anywhere near an open pilot. My workshop is in the basement. We have natural gas furnaces and a tankless gas hot water heater. But my shop is an enclosed room that encompasses 1/2 of the basement. The furnace has its own room and the hot water heater is mounted on the opposite wall, across the basement.

Right now, I have a makeshift area in my shop that I close off with shower curtains, in front of a window. I have a strong double fan in the window, blowing out, to exhaust the over spray. I have a second window in the shop area, and I have another double fan that brings air into the shop area. So in essence, I have cross ventilation. My husband worked in HVAC for over 50 years. He's going to install a through the wall blower unit which will replace the double fan.

The first time I sprayed, you could smell the stuff clear to the third floor of our house. After using the 2 windows and double fans, it vents it really well. I wear a 3M, full face mask, rated for VOC's, plus an old lab coat, gloves, and a shower cap. If anyone saw me, they'd think I'm working in a biolevel 4 lab. LOL

I completely understand the hand cramping. I had Carpel tunnel surgery on both hands 15 years ago. After I built my first guitar, it came back with a vengeance, along with the added attraction of both of my thumbs triggering. The VA hand specialist did revisions and trigger release.

I love French polishing. It may not be the preferred technique, but I've learned to use firm, but not hard pressure. I save the donkey Kong pressure for spiritng off. I've found that I persevere longer, if I temper my approach. Also, there's no law that dictates that you have to work on it daily. If you keep working when you have hand pain, it can turn into something more serious. So, even if you only do 1 coat 2x pet day, it's okay. You don't need tendonitis. It takes me a long time to fp a guitar. Shellac brings out the depth and beauty of the woods.

I'm currently starting 3 new builds. These photos are of a Brazilian rosewood build that I'm stringing up for the first time tomorrow. It literally took me months to polish this guitar. I worked on it for a few days, then I allowed it to sit for a few days to harden. I followed this routine for a long time. If you ask how many coats are on this guitar, I wouldn't be able to tell you. It's a lot. But it shows you that you can French polish effectively, even with severely reduced hand strength.

I've learned to listen to my hands. I still power through the cramps at times to finish what I'm doing, but if I get warning signs, I rest them.
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Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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