Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Thu Mar 28, 2024 10:17 am


All times are UTC - 5 hours





Post new topic Reply to topic  [ 22 posts ] 
Author Message
PostPosted: Tue Nov 08, 2022 11:45 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
I’ve sprayed nitro lacquer on about 60 instruments and have never seen this before.
Behlen instrument lacquer over Zpoxy.
Mahogany neck, Cebil fretboard.
I’ll sand it down and reshoot.
The other side of the board looks fine.
I suspect water somehow wicked in during wet sanding.

Does anyone have a clue as to why this happened?

Can I just sand the affected area and reshoot lacquer including the polished surfaces?


You do not have the required permissions to view the files attached to this post.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Tue Nov 08, 2022 2:00 pm 
Offline
Cocobolo
Cocobolo
User avatar

Joined: Fri Apr 13, 2007 12:52 am
Posts: 285
Location: Canada
First name: Cal
Last Name: Maier
City: Crossfield
State: AB
Country: Canada
Focus: Build
Status: Professional
Not sure what caused the peeling, maybe water, but you need to sand the glossy parts in order for the nitro to stick there.

Best to scuff the shine off before spraying.

Cal

_________________
Remember, there are no stupid questions, only stupid answers!



These users thanked the author Cal Maier for the post: dzsmith (Tue Nov 08, 2022 2:05 pm)
Top
 Profile  
 
PostPosted: Tue Nov 08, 2022 2:38 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
I started scraping the affected area and found out the lacquer on the entire neck can be peeled off.
I’m using a razor blade with a burnished edge.
Not sure how I will remove the lacquer. I may try thinner or acetone.
Hopefully the color under the Zpoxy will not get buggered up.
I have no issues with the body, I sprayed the body and neck separately.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Tue Nov 08, 2022 3:59 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3227
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
Water would not cause this. You might have a contaminate like wax or silicone that prevented burn in between layers.



These users thanked the author Barry Daniels for the post: dzsmith (Tue Nov 08, 2022 5:17 pm)
Top
 Profile  
 
PostPosted: Tue Nov 08, 2022 6:41 pm 
Offline
Koa
Koa

Joined: Mon Jul 11, 2005 5:17 am
Posts: 995
Location: United States
City: Tyler
State: Texas
If removed lacquer off necks with lacquer thinner. Wipes right off.



These users thanked the author Glen H for the post: dzsmith (Tue Nov 08, 2022 8:16 pm)
Top
 Profile  
 
PostPosted: Fri Nov 18, 2022 6:19 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
I scraped the lacquer off and cleaned up with lacquer thinner.
There was a two month period from first to last lacquer applications.
Maybe I should have thinned the lacquer when I started the delayed second application to allow it to burn in?

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Tue Nov 22, 2022 7:33 pm 
Offline
Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
Posts: 951
First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
Focus: Build
Status: Amateur
I'm an amateur at finishing. What I'm reading about is a neck that got contaminated with something between finishing sessions. Was there any activity in the building that would have created a cloud of wax/silicone/cooking grease/cooking oil that might have made its way to the neck? Clouds can be awfully diluted and still cause trouble.

_________________
Peter Havriluk


Top
 Profile  
 
PostPosted: Wed Nov 23, 2022 10:22 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
phavriluk wrote:
I'm an amateur at finishing. What I'm reading about is a neck that got contaminated with something between finishing sessions. Was there any activity in the building that would have created a cloud of wax/silicone/cooking grease/cooking oil that might have made its way to the neck? Clouds can be awfully diluted and still cause trouble.


I blew off the dust and cleaned with Naptha prior to spraying.
The neck was hanging in my shop, I can’t imagine it got contaminated.
Good point, and possible.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Wed Nov 23, 2022 8:23 pm 
Offline
Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
Posts: 951
First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
Focus: Build
Status: Amateur
Any chance that the cloth used in wiping down with naphtha was contaminated with something, something from the household and not from new cleaning cloth?

_________________
Peter Havriluk


Top
 Profile  
 
PostPosted: Wed Nov 23, 2022 9:28 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
phavriluk wrote:
Any chance that the cloth used in wiping down with naphtha was contaminated with something, something from the household and not from new cleaning cloth?


No, I use Kimberly Clark paper towels that I store in a closed plastic container.
I’m careful about keeping these perfectly clean. I never reuse one.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Thu Nov 24, 2022 11:11 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3227
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
I worked at Intl. Luthier Supplies back in the '70s and we had a customer that had varnish peeling off his newly built violin. It took some inquiry but we finally realized he was using a "furniture polishing cloth" as a tack rag that he had purchased for this purpose. Problem was that the cloth was saturated with silicone. Not saying this is your issue, but that it can be unexpected where contaminants can show up. For example, some sandpaper has stearate which creates similar problems.



These users thanked the author Barry Daniels for the post: dzsmith (Thu Nov 24, 2022 12:35 pm)
Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 4:26 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
I sanded the neck to bare wood, added color, and sprayed two coats of thinned lacquer.
i noticed the lacquer in the can was cloudy and sprayed anyways (what a dummy).
I added thinner and stirred it but still cloudy.
Maybe the lacquer was bad when I first sprayed the neck and caused the failure.
I bought it this year, no extreme heat or cold.
I guess I’ll sand the existing lacquer and hope I don’t muck the color (dye).
Does lacquer go bad?

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 6:41 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3227
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
I have had 10 year old lacquer that still worked fine. However, it was stored in a glass jar. But one year old lacquer is not the problem. May have just been a bad mix.


Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 7:05 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
Barry Daniels wrote:
I have had 10 year old lacquer that still worked fine. However, it was stored in a glass jar. But one year old lacquer is not the problem. May have just been a bad mix.

Thanks,
I sent a query to Mohawk with the lot number.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 7:17 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3227
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
The cloudy stuff suggests some ingredient that shouldn't be there.


Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 7:32 pm 
Offline
Koa
Koa

Joined: Mon Jul 11, 2005 5:17 am
Posts: 995
Location: United States
City: Tyler
State: Texas
I think it can go bad. I had some lacquer that turned real dark while stored. Way off color. I threw it out.


Top
 Profile  
 
PostPosted: Tue Dec 06, 2022 7:39 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sun Mar 06, 2011 12:04 am
Posts: 5743
First name: Chris
Last Name: Pile
City: Wichita
State: Kansas
Country: Good old US of A
Focus: Repair
Status: Professional
Real nitro is organic, so I guess anything could happen.

_________________
"Act your age, not your shoe size" - Prince


Top
 Profile  
 
PostPosted: Wed Dec 07, 2022 9:03 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3227
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
It's not like food. There is no bacteria that could ever live in lacquer. The only possibility I see is some type of chemical reaction. But I think it is much more likely that someone did an improper mix. Whatever it is, I would throw it out.



These users thanked the author Barry Daniels for the post: dzsmith (Wed Dec 07, 2022 9:25 am)
Top
 Profile  
 
PostPosted: Wed Dec 07, 2022 11:58 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
Barry Daniels wrote:
The cloudy stuff suggests some ingredient that shouldn't be there.


I spoke with the Mohawk dude.
He said if it’s cloudy, it’s contaminated and not to use it.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Sat Jan 21, 2023 9:15 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Mon Jan 28, 2008 5:21 am
Posts: 4839
Location: Central PA
First name: john
Last Name: hall
City: Hegins
State: pa
Zip/Postal Code: 17938
Country: usa
Focus: Build
Status: Professional
how find did you sand? past 220 and you loose tooth
a did you seal the wood before spray and what sealer did you use
what stain did you use and what filler

I have had this happen one time using vinyl sealer . thought 4 coats would be good
nope sealer 1 coat is all you need. Also did you thin?

finish work is about as much on technique as it is what you spray.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it


Top
 Profile  
 
PostPosted: Sat Jan 21, 2023 10:50 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri May 18, 2012 8:35 pm
Posts: 2658
Location: Austin, Texas
First name: Dan
Last Name: Smith
City: Round Rock
State: TX
Zip/Postal Code: 78681
Country: USA
Focus: Build
Status: Amateur
bluescreek wrote:
how find did you sand? past 220 and you loose tooth
a did you seal the wood before spray and what sealer did you use
what stain did you use and what filler

I have had this happen one time using vinyl sealer . thought 4 coats would be good
nope sealer 1 coat is all you need. Also did you thin?

finish work is about as much on technique as it is what you spray.



Thanks John,
I applied alcohol based dye to bare wood, Zpoxy grain fill, sanded to 220.
No sealer. I shot Behlen nitro full strength, thick coats.

Repair:
I sanded everything back to bare wood. Applied dye and Zpoxy.
I thinned the (new can) lacquer and built up thin wet coats.
So far, it looks fine and I don’t see any evidence of peeling.

_________________
wah
Wah-wah-wah-wah
Wah


Top
 Profile  
 
PostPosted: Thu Apr 13, 2023 3:35 am 
Offline
Mahogany
Mahogany

Joined: Thu Oct 21, 2021 4:23 pm
Posts: 42
First name: Yeaux
Last Name: Maumma
Focus: Repair
Status: Professional
I’ve had this happen before. Usually it happens on a instrument in for repair and never when I’m building as I use automotive product or water base for the most part. With nitro tho,What I always do is add lacquer retarder to the clear coat. It allows the nitro more time to melt into the previous layer/layers. It won’t help with spraying directly to zpoxy as that is a mechanical bond, but it will help nitro melt into the previous layer.


Sent from my iPhone using Tapatalk



These users thanked the author Lou Thier for the post (total 2): dzsmith (Sun Apr 16, 2023 11:01 am) • Chris Pile (Thu Apr 13, 2023 10:07 am)
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 22 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 17 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com