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  #1  
Old 09-15-2017, 05:14 PM
Quickstep192 Quickstep192 is offline
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Default A question for those who pore fill with epoxy

For those who use epoxy for pore filling....

If you're pore filling oily or problem woods like cocobolo, do you seal the wood with shellac first before applying the epoxy?

If so, do you also use shellac on top of the epoxy before applying lacquer?
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  #2  
Old 10-02-2017, 12:49 AM
CE Sobel CE Sobel is offline
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I do french polish not lacquer but I always do one or two seal coats of shellac before doing the pore fill with epoxy regardless of the oil content of the wood.
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Old 10-02-2017, 02:42 PM
cobalt60 cobalt60 is offline
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Originally Posted by CE Sobel View Post
I do french polish not lacquer but I always do one or two seal coats of shellac before doing the pore fill with epoxy regardless of the oil content of the wood.
Only consideration if you try shellac followed by epoxy: You may have color splotches where you sand through the epoxy and shellac vs. not through the shellac, even if the shellac is very blond.
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Old 10-02-2017, 08:36 PM
Shuksan Shuksan is offline
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According to posts from several builders over on the OLF, you can put shellac over epoxy, but not epoxy over shellac. If you search the OLF with "epoxy + shellac + pore + fill" you'll fine some threads that address this.
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Old 10-03-2017, 11:21 AM
cobalt60 cobalt60 is offline
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I'm not familiar with those discussions, but personally, I almost always have a spit coat of shellac over every surface pre-finish, applied in the French polish style. In my life, this helps seal off any weird surface oils, exposes any residues, etc. but maybe that's not good for everyone out there.
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  #6  
Old 10-03-2017, 08:39 PM
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WaddyT WaddyT is offline
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Originally Posted by Shuksan View Post
According to posts from several builders over on the OLF, you can put shellac over epoxy, but not epoxy over shellac. If you search the OLF with "epoxy + shellac + pore + fill" you'll fine some threads that address this.
I have read many posts on OLF and other forums with this same information. I have used Zpoxy on one guitar, and it went on a Cocobolo instrument. Worked fine on bare wood.
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Old 10-04-2017, 11:43 AM
Howard Klepper Howard Klepper is offline
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Originally Posted by cobalt60 View Post
Only consideration if you try shellac followed by epoxy: You may have color splotches where you sand through the epoxy and shellac vs. not through the shellac, even if the shellac is very blond.
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Originally Posted by Shuksan View Post
According to posts from several builders over on the OLF, you can put shellac over epoxy, but not epoxy over shellac. If you search the OLF with "epoxy + shellac + pore + fill" you'll fine some threads that address this.
I stopped visiting OLF several years ago, mainly because it was dominated by a few amateur builders who thought that theirs was the only way to do things, and were uninterested in hearing about alternatives. The newby amateur builders who went there just wanted to know how "everybody" does it and followed the loudest voices. So pretty much every professional who tried to post there and talk more about how things work so people could understand how to choose their own methods gave up and left. I see things have not changed.

So there is a method there that "everybody" uses for epoxy pore fills, and their groupthink is that it is the only method. That OLF method is to use an epoxy finishing resin called Zpoxy, put it on bare wood, and put it on thick enough that it can be leveled without sanding through. I guess it works for those who use it, although I imagine sand-throughs are an issue.

But . . . it is utter hogwash that one cannot put epoxy over shellac. I've been doing it for about 15 years with no problems. I do not use Zpoxy or any other epoxy intended as a finish, because I am only using it for pore fill. I use 5-minute epoxy because it saves days of waiting for slower epoxy to dry. I put a thin coat of dewaxed shellac on first. I squeegee the epoxy in to the pores with a dulled and corners-rounded single edge razor blade, trying to force it down in the pores and leave as little as possible on the surface. [It helps to mix no more than a couple of pea sized dabs of resin and hardener at a time, because until you get fast at it, that's all you can spread before it starts to set; and keep cleaning your razor with an small rag wet with alcohol]

When it's hard (overnight) I sand back to wood, which avoids any issue of irregular color. As I said, the epoxy is there to fill pores, not to be a finish coat. No further sealing is needed before lacquering. Nitro lacquer has no need for anything between it and wood.

BTW, I learned this method by talking with Bob Milburn, who is well-known for french polishing instructions. Ironically, while his and his father Orville's FP instructions tell how to fill with pumice, he told me 15 years ago that he never did that anymore because the epoxy works so much better. 'Better' is the significant and highly relative term, because I have tried every type of filler, and now use three different kinds depending on the wood and the results desired, and still never get a perfect fill with one application. Get used to frustration, don't believe the ad copy about any filler, refill sooner than later, and learn to drop fill.
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Last edited by Howard Klepper; 10-04-2017 at 01:27 PM.
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  #8  
Old 10-04-2017, 12:21 PM
charles Tauber charles Tauber is offline
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Originally Posted by Howard Klepper View Post
Ironically, while his and his father Orville's FP instructions tell how to fill with pumice, he told me 15 years ago that he never did that anymore because the epoxy works so much better.
Nice. Thank you, Howard, for sharing that.
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Old 10-04-2017, 01:51 PM
redir redir is offline
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I'm very glad you shared that too Howard. I've had this conversation on OLF myself and thought it was strange that your would not use epoxy as a pore filler but rather as a finish itself! I don't want to slather epoxy all over my instrument just to fill the pores. With regular oil based fillers which I have used for 20+ years you fill, sand back to wood, and leave the pores filled. Makes perfect sense.

I then red the Millburn guitar tortorial on French Polish which was basically how I learned to FP and later on he edited that tutorial to include filling with 5min epoxy - boom done!

But I've been turned off from epoxy based on all those zpoxy instructions, more afraid to use it then turned off but I just might give it a go now.

Do you recommend a particular brand? Millburn said he just uses regular old hardware store 5min epoxy. I have noticed that the Locktite brand seems to dry reasonably clear.
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Old 10-04-2017, 02:03 PM
Shuksan Shuksan is offline
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Originally Posted by Howard Klepper View Post
I stopped visiting OLF several years ago, mainly because it was dominated by a few amateur builders who thought that theirs was the only way to do things, and were uninterested in hearing about alternatives. The newby amateur builders who went there just wanted to know how "everybody" does it and followed the loudest voices. So pretty much every professional who tried to post there and talk more about how things work so people could understand how to choose their own methods gave up and left. I see things have not changed.
It's too bad you had a bad experience back then with the OLF, but by your own admission that was several years ago when you stopped visiting the forum. It's hard to see how that leaves you a position to be bad mouthing the forum today.

Quote:
Originally Posted by Howard Klepper View Post
So there is a method there that "everybody" uses for epoxy pore fills, and their groupthink is that it is the only method. That OLF method is to use an epoxy finishing resin called Zpoxy, put it on bare wood, and put it on thick enough that it can be leveled without sanding through. I guess it works for those who use it, although I imagine sand-throughs are an issue.
Unfortunately, this has many errors
-The method you refer to is used by a small subset of forum members.
- There is no such thing as "That OLF method". The method exists independent of the forum.
- There is no "groupthink" about it. I don't know of a single member who has claimed it is the only method. It's an option that forum readers can choose to use, or not, as they see fit.
- Not sanding z-poxy back to the wood is just one of the ways to use it.
- If you had read about the method instead of "imagining" you would have found that sand-throughs are not a problem. At least for anyone who is competent at surface prep and sanding.

Quote:
Originally Posted by Howard Klepper View Post
" theirs was the only way to do things, and were uninterested in hearing about alternatives. "
With regards to the z-poxy method, this sounds a bit like the pot calling the kettle black.


Quote:
Originally Posted by Howard Klepper View Post
But . . . it is utter hogwash that one cannot put epoxy over shellac. I've been doing it for about 15 years with no problems. I do not use Zpoxy or any other epoxy intended as a finish, because I am only using it for pore fill. I use 5-minute epoxy because it saves days of waiting for slower epoxy to dry. I put a thin coat of dewaxed shellac on first. I squeegee the epoxy in to the pores with a dulled and corners-rounded single edge razor blade, trying to force it down in the pores and leave as little as possible on the surface. [It helps to mix no more than a couple of pea sized dabs of resin and hardener at a time, because until you get fast at it, that's all you can spread before it starts to set; and keep cleaning your razor with an small rag wet with alcohol]

When its hard (overnight) I sand back to wood, which avoids any issue of irregular color. As I said, the epoxy is there to fill pores, not to be a finish coat. No futher sealing is needed before lacquering. Nitro lacquer has no need for anything between it and wood.

BTW, I learned this method by talking with Bob Milburn, who is well-known for french polishing instructions. Ironically, while his and his father Orville's FP instructions tell how to fill with pumice, he told me 15 years ago that he never did that anymore because the epoxy works so much better.
Thank you for sharing your experience that's relevant to the OP's questions.
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Old 10-04-2017, 02:10 PM
Truckjohn Truckjohn is offline
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Quote:
Originally Posted by Howard Klepper View Post
I stopped visiting OLF several years ago, mainly because it was dominated by a few amateur builders who thought that theirs was the only way to do things, and were uninterested in hearing about alternatives. The newby amateur builders who went there just wanted to know how "everybody" does it and followed the loudest voices. So pretty much every professional who tried to post there and talk more about how things work so people could understand how to choose their own methods gave up and left. I see things have not changed.
*Sigh*. What has changed is the place its almost empty now.. Nobody posts builds.. Nobody cares if builds are posted... No interest.

Anyway... Shellac will stick to nearly anything.

Howard's point about the time required is a good one.... The concern is to make sure the epoxy is *fully* cured out before coating shellac over it. The shellac will still dry right over top of uncured epoxy... And then it will crack up to pieces or flake off... The alcohol will also dissolve uncured epoxy and make a mess.. Its not really a shellac problem - its an uncured epoxy problem....

I like to run a hair dryer over epoxy on Day #2.. It seems to help make sure everything is good and cured out - no sticky, mushy, etc....
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Old 10-04-2017, 02:18 PM
redir redir is offline
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FWIW I still score some really descent stuff over in the OLF classifieds. There are still some good people there and reputable builders willing to give advice. I think maybe the fact that it is NOT so active might actually be a better thing in a way.
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  #13  
Old 10-04-2017, 03:21 PM
Howard Klepper Howard Klepper is offline
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Quote:
Originally Posted by Shuksan View Post
It's too bad you had a bad experience back then with the OLF, but by your own admission that was several years ago when you stopped visiting the forum. It's hard to see how that leaves you a position to be bad mouthing the forum today.



Unfortunately, this has many errors
-The method you refer to is used by a small subset of forum members.
- There is no such thing as "That OLF method". The method exists independent of the forum.
- There is no "groupthink" about it. I don't know of a single member who has claimed it is the only method. It's an option that forum readers can choose to use, or not, as they see fit.
- Not sanding z-poxy back to the wood is just one of the ways to use it.
- If you had read about the method instead of "imagining" you would have found that sand-throughs are not a problem. At least for anyone who is competent at surface prep and sanding.



With regards to the z-poxy method, this sounds a bit like the pot calling the kettle black.




Thank you for sharing your experience that's relevant to the OP's questions.
Perhaps it's just my own incompetence at surface prep and sanding. Thanks for the corrections. Although I did do all the reading about the "Zpoxy method" (is that an OK name?), and I did consider it as an alternative. And I did find that there was no one interested in hearing how the Milburn method worked--they were pretty insistent that there was only one epoxy method, and that the epoxy should not be sanded back to wood. It was your posting that the word on OLF (in multiple threads) is that you can't use epoxy over shellac that led me to conclude that things have not changed, but I'm very glad to learn that they have. You may not have been around there at the time, but there were multiple posts and even whole threads about why no professionals ever stayed around.
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Last edited by Howard Klepper; 10-04-2017 at 07:01 PM.
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  #14  
Old 10-04-2017, 03:51 PM
Howard Klepper Howard Klepper is offline
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Howard's point about the time required is a good one.... The concern is to make sure the epoxy is *fully* cured out before coating shellac over it. The shellac will still dry right over top of uncured epoxy... And then it will crack up to pieces or flake off... The alcohol will also dissolve uncured epoxy and make a mess.. Its not really a shellac problem - its an uncured epoxy problem....
Thanks, John, but that was not my point. I don't put shellac over epoxy. I was talking about not sanding until the epoxy is hard, which takes overnight to be safe even for 5 minute. If you sand too soon, you will pull the epoxy out of the pores and clog your sandpaper.
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