Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Thu Mar 28, 2024 7:01 am


All times are UTC - 5 hours


Forum rules


Be nice, no cussin and enjoy!




Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 7:05 am 
Offline
Cocobolo
Cocobolo

Joined: Wed Dec 22, 2010 12:49 pm
Posts: 273
First name: Victor
Last Name: Seal
City: Osseo
State: MI
Zip/Postal Code: 49266
Country: USA
Focus: Build
Status: Amateur
What is the advantage of Zpoxy over regular old hardware store epoxy?


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 7:55 am 
Offline
Contributing Member
Contributing Member

Joined: Sat Aug 27, 2011 1:59 pm
Posts: 374
First name: Ken
Last Name: Lewis
City: Mt. Pearl
State: NL
Country: Canada
Focus: Build
Status: Amateur
Zpoxy as well as other epoxy pore fillers, West, System 3 are finishing resins which allow spreadability, good working time and
they cure rock hard. Hardware store variety not so much.


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 9:38 am 
Offline
Cocobolo
Cocobolo

Joined: Wed Dec 22, 2010 12:49 pm
Posts: 273
First name: Victor
Last Name: Seal
City: Osseo
State: MI
Zip/Postal Code: 49266
Country: USA
Focus: Build
Status: Amateur
Thanks. Never used epoxy filler and getting ready to fill craters.


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 11:08 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Jul 27, 2015 8:21 am
Posts: 3288
First name: Brad
Last Name: Combs
Focus: Build
Status: Amateur
Zpoxy has an amber tint to it as well, that might affect which wood species you want to use it on.


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 3:18 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
A caution for the first-time user: Squeegee off as much as you can after each application, and there will be at least two applications involved, plus a final wipe coat to make sure the entire surface is sealed. And neatness is seriously necessary, very seriously necessary. Ain't like paint.

_________________
Peter Havriluk


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sat Jun 30, 2018 3:59 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sat Dec 30, 2006 3:20 am
Posts: 2593
Location: Powell River BC Canada
First name: Danny
Last Name: Vincent
It dries clear. Others may not.


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sun Jul 01, 2018 8:23 am 
Offline
Walnut
Walnut

Joined: Fri Aug 11, 2017 12:27 pm
Posts: 3
First name: Dan
Last Name: Hill
City: Chadds Ford
State: Pennsylvania
Zip/Postal Code: 19317
Country: United States
Focus: Build
Status: Amateur
phavriluk wrote:
A caution for the first-time user: Squeegee off as much as you can after each application, and there will be at least two applications involved, plus a final wipe coat to make sure the entire surface is sealed. And neatness is seriously necessary, very seriously necessary. Ain't like paint.


Peter,
How does your final wipe coat differ from the first two squeegee coats and do you sand down virtually to bare wood after it?
-d.


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sun Jul 01, 2018 10:04 am 
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
Final wipe coat is insurance against having inadvertently cut through the filler coats. Thin, padded on with a cloth. Light sanding to knock off the dust that might have gotten into it. I did all my leveling before applying the wipe coat.

_________________
Peter Havriluk


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sun Jul 01, 2018 10:39 am 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1831
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
Z-Poxy is a 50/50, non-critical mix finishing resin, but will blush if in higher humidity, as faster-curing epoxies like Z-Poxy tend to generate more blush. It's important to clean off any blush with liquid detergent, water, and a maroon ScotchBrite pad, as it will interfere with subsequent coats of sealer and finish, and will eventually react with anything that passes through the wood or finish. Some epoxy manufacturers suggest that water alone is the preferred solvent for blush, so worth checking with the maker of the system. Dry sanding the surface without first removing the blush will not clear the contamination and instead will work the blush into the sanding scratches.

A second caution is that the Z-Poxy hardener darkens with age, and a sand-through on a final coat can show a light spot on rosewoods. Another of the schools of epoxy practice used a heavy coat of epoxy and heat to level..with the issue that the thicker the coating, the more amber-appearing. Very thin coatings add the least film thickness and result in the most uniform color.

Finally, thinning beyond 10% or so with denatured alcohol can slow the cure a bit and introduce water into the uncured resin, which can result in a softer film. This thicker viscocity is one of the issues we've seen with Z-Poxy...while the material runs a bit less than low and low-to-medium viscosity systems, it also does not tend to penetrate as nicely into pores.

West, Maas, and System 3 all make low-blush or non-blushing formulations, but the one we've found we like the best is System 3 Silver Tip with their fast hardener...the viscosity is perfect - not too thick or too thin, clear, and not too critical on the mix in very small batches (we do 5 grams resin for normal work, but have mixed down to 2.5 grams resin using a sensitive scale). With the fast hardener, a second or third coat can be applied without sanding if done in 72 hours or less, but we lightly scrape with a razer blade scraper and tooth with maroon ScotchBrite anyway - if only to keep surface build down to a minimum.

FWIW, there are a couple videos on YouTube that cover pore filling with epoxy, including with Z-Poxy (search for 'guitar Z-Poxy pore filling') - with a well-engineered holder for the body and neck, back and sides can be done in one session.

The Etore or similar window squeegee is the real key to any epoxy pore filling. Unlike a Bondo squeegee or credit card, a thick-edged window washing squeegee can generate some real pressure to force the epoxy in the pores, as well as stripping off excess epoxy so as to leave the thinnest film. With Silver Tip being water-clear, we don't worry about a sand-through on the first two coats, but do leave a thin, continuous layer for the final coat, toothing it with ScotchBrite for a good mechanical bond with sealers or topcoat.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)



These users thanked the author Woodie G for the post (total 3): CraigG (Tue Jul 03, 2018 6:44 am) • TimAllen (Mon Jul 02, 2018 11:48 am) • Danl8 (Sun Jul 01, 2018 3:09 pm)
Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Sun Jul 01, 2018 3:16 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
You will want an epoxy that bonds well with what you are pore filling (wood? oily wood, sealed wood?), is designed to be applied thin, as in finishing resin, won't turn green as it cures, and is user friendly. And you will want to choose an epoxy that has demonstrated compatibility with the finishing system you plan to use.

Typical choices are Zpoxy, or products from System Three and West Systems.

_________________
Joe Beaver
Maker of Sawdust


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Mon Jul 02, 2018 1:22 am 
Offline
Koa
Koa
User avatar

Joined: Mon Sep 05, 2011 10:45 pm
Posts: 1470
First name: Trevor
Last Name: Gore
City: Sydney
Country: Australia
Focus: Build
Status: Professional
If you go with the WEST System, be sure to use the 207 hardener to avoid any potential for blush problems.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Mon Jul 02, 2018 7:40 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 6232
Location: Virginia
Milburn uses the cheap hardware stuff in his French Polish tutorial. I have only used epoxy once and I just used Loctite 5-minute from the hardware store. But like Milburn I also use the epoxy like a traditional filler and sand back to wood leaving only the pores filled.


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Mon Jul 02, 2018 12:15 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
Trevor brings up a good point, blush. It happens with some epoxys in the right conditions. I currently use System Three Clear Coat, it doesn't blush, and as Trevor said West System with the right hardener won't either. Zpoxy will blush if the RH is up.

To reduce the chances of blush you can use humidity control in the work area. If you don't have that you can reduce the risk by warming the wood with a heat gun or hair dryer just before appling the epoxy. That seems to work when you have moderately high RH (say 45-55). I haven't tried with higher RH.

_________________
Joe Beaver
Maker of Sawdust


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Mon Jul 02, 2018 5:59 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Sep 05, 2011 10:45 pm
Posts: 1470
First name: Trevor
Last Name: Gore
City: Sydney
Country: Australia
Focus: Build
Status: Professional
The trouble with the non-specialist epoxies (used for laminating, gluing, filling rather than surface coating) is that they can go white on you way down the track, like a couple of years. So be sure you use an epoxy system especially formulated not to blush. The WEST 105 resin + 207 hardener is one of these systems. There are others, but I know the WEST system works for me and I don't fancy finding out in a couple of years that another system doesn't.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Mon Jul 02, 2018 7:10 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Apr 16, 2012 12:47 pm
Posts: 2422
First name: Jay
Last Name: De Rocher
City: Bothell
State: Washington
Has anyone here seen blush occur with System Three, West, or Z-poxy under finish on a guitar after a couple years (or more)? If so, under what conditions did it happen?

Along with humidity and temperature, how much of a factor is application thickness in blushing?

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 2:31 am 
Offline
Koa
Koa
User avatar

Joined: Mon Sep 05, 2011 10:45 pm
Posts: 1470
First name: Trevor
Last Name: Gore
City: Sydney
Country: Australia
Focus: Build
Status: Professional
J De Rocher wrote:
Has anyone here seen blush occur with System Three, West, or Z-poxy under finish on a guitar after a couple years (or more)? If so, under what conditions did it happen?

Along with humidity and temperature, how much of a factor is application thickness in blushing?

Yes, WEST with 206 hardener (should have used 207). Guitar stored in a soft case at typ. 60% humidity, developed white patches after ~2 years. Coating thickness was full cover, but as thin as I could get it. I didn't measure it. I don't know if thickness is a factor, but a continuous film will likely give a more visible problem than a pore fill sanded back to the wood. The application temp. would have been above 25C and the RH close to 45%. I still have the guitar (it is the original falcate braced prototype) and the white area has grown and intensified over the years.

WEST with 206 won't always go white on you, but WEST with 207 never has for me.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au



These users thanked the author Trevor Gore for the post: J De Rocher (Tue Jul 03, 2018 10:45 am)
Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 5:44 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Mar 30, 2008 8:20 am
Posts: 5924
"WEST with 206 won't always go white on you, but WEST with 207 never has for me."

Do you think it was amine blush or the reaction to ultraviolet light that caused it to go cloudy? The 207 has UV protection added, which supposedly still works even after the hardener has turned dark amber (as it will after a couple of years - which gives a light amber tint to the mixed epoxy).


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 7:01 am 
Offline
Koa
Koa
User avatar

Joined: Mon Sep 05, 2011 10:45 pm
Posts: 1470
First name: Trevor
Last Name: Gore
City: Sydney
Country: Australia
Focus: Build
Status: Professional
Clay S. wrote:
Do you think it was amine blush or the reaction to ultraviolet light that caused it to go cloudy?

I doubt it was any reaction to UV as that guitar spent most of its time in a case. More likely some sort of reaction to humidity after initial cure, but whether it would be technically correct to call that amine blush or just "bloom" is a different matter.

It was finished in nitro and buffed out perfectly clear, so initially there was no apparent issue. That's the scary bit!

Here's some background on WEST 207 Hardener. Read between the lines for the implications regarding the other hardeners. For example, "206 Slow Hardener is not intended for clear coating" quoted from the WEST 206 page. I like it that WEST are very specific about the performance of 207. I've found it problematical getting other suppliers to match WEST's statements so emphatically.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 8:03 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Mar 30, 2008 8:20 am
Posts: 5924
www.oneoceankayaks.com/Epoxresl.htm#blush

Kayak builders use clear epoxy coatings for some of their boats. Here is a test one of them did on various epoxies


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 8:17 am 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1831
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
We have seen separation of lacquer finish over time due at least partially to reaction of moisture passing through the lacquer (excessively acidic perspiration left on the instrument over an extended period of time) with the amine salts (carbomates) which were not fully removed. At first, we believed this was epoxy shrink-back in the pores causing mechanical separation, but have seen the same thing occur even where woods without significant pores (maple; cherry) were treated with Z-Poxy to add a layer of higher index-of-refraction material to the finish.

The finish separation appears to be confined to just a few guitars, and to owners who perspire heavily and have out-of-the norm body chemistry (very acidic...4.5-5.0, although some studies claim normal male perspiration is closer to 5.5 than the 7.0 for females). We suspect the alkaline carbomate residue is reacting with the lower pH perspiration which is passed through the lacquer film over time, with the reaction products creating a visible residue and forcing separation of the sealer from the epoxy.

The other factor is amine bloom, which is different from blush, and is the unreacted amine component of the epoxy migrating to the surface...this waxy-appearing haze on the surface is easier to detect than the blush, as at the RH we apply epoxy (45%-50% RH), the amount of blush may be undetectable by visual inspection and the pH test may be inconclusive (indicates conditions are conducive to blush and bloom, versus the presence of those compounds). Accurate mixing can help with bloom, and in any case, bloom may or may not react with atmospheric CO2 and water vapor and be converted to carbomate (blush).

Both blush and bloom can cause issues with subsequent finish operations, which - after using Z-Poxy (blush prone), West 105/207 (minimal blush/bloom and usually free of both at our shop temperature and RH), and Maas Low Viscosity (poor handling) - led us to System 3 SilverTip (as well as Mr. Greven's use) , which is essentially blush and bloom-free even in small quantity mixes, and has excellent handling characteristics. Even then, we do a water and detergent wash-down and a distilled water rinse with final naphtha wipe before sealing.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)



These users thanked the author Woodie G for the post: J De Rocher (Tue Jul 03, 2018 12:10 pm)
Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 12:41 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
Woodie, good report, thank you for posting. One question, why has Silvertip been chosen as oposed to Clear Coat?

_________________
Joe Beaver
Maker of Sawdust


Last edited by Joe Beaver on Tue Jul 03, 2018 1:38 pm, edited 2 times in total.

Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 12:57 pm 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1831
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
Handling, mix sensitivity, cure time, and recoat time. The viscosity is just right out of the containers for pore filling, versus Clear Coat, which is just a bit thinner than we prefer. Pretty insensitive to mix ratio, which is an issue with some System 3 epoxies. With fast hardener, 2-3 coats a day are possible, depending on ambient temperature, and no-sand recoat up to 72 hours.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 1:46 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
Thanks Woodie,
Just curious why Silvertip was chosen since it is a lamenting epoxy, designed to bond fiberglass cloth to wood, whereas Clear Coat is designed as a finishing epoxy.

That doesn't mean one is inherently better than the other for our purpose.

_________________
Joe Beaver
Maker of Sawdust


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 4:00 pm 
Offline
Koa
Koa
User avatar

Joined: Sat Jan 19, 2013 7:33 am
Posts: 1831
First name: Willard
Last Name: Guthrie
City: Cumberland
State: Maryland 21502
Zip/Postal Code: 21502
Country: United State
Focus: Repair
Status: Semi-pro
Both are billed as suitable for raw wood, so not an issue there. Really a case of a perfect viscosity, faster cure, and generally better handling characteristics without having to either bulk or thin. After the latest cycle of 10 new guitars and two refinishes (one full and one partial), plus a couple minor furniture projects, I really began to appreciate the 'not too thick/not too thin' characteristics. Comes down to preference, with the boss still preferring the higher viscosity of the Z-Poxy, but really disliking the blush issues.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)


Top
 Profile  
 
 Post subject: Re: Epoxy pore fill
PostPosted: Tue Jul 03, 2018 4:31 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Apr 16, 2012 12:47 pm
Posts: 2422
First name: Jay
Last Name: De Rocher
City: Bothell
State: Washington
I haven't seen any blushing with Z-poxy, yet. The oldest guitar I've built that has Z-poxy on it is three years old and it's fine. I always apply Z-poxy with the room temperature at least 70 degrees F, RH = 45-50%, and let it sit overnight between applications. Maybe I've just been lucky so far. I like Z-poxy, but if Silver Tip is less susceptible to blushing, it might be wise for me to switch to it for the added insurance. I'll give it a try on the current guitar when I get to that point.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: Ken Nagy and 47 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