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PostPosted: Wed Feb 06, 2019 7:22 pm 
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Koa
Koa

Joined: Thu Sep 10, 2009 4:01 pm
Posts: 1887
Location: UK
Steven Odut wrote:
My experience with pigment based grain fillers is that they dry so quickly that it is hard to wipe on/wipe off in time, resulting in the need for tiresome sanding to remove excess material from the surface of the wood. With these grain fillers I fill about 1/4 of the back before having to start wiping off before it starts to set.

Also, although epoxy has it's health hazards, one of the clear grain fillers I bought stated that it was a teratogen on the MSDS (so if you're looking to become a parent in the near future, it might not be a good choice).


Were the grain fillers oil based? If oil based it's best to use an open woven coarse cloth like hessian to remove the excess. Also a cotton cloth just slightly dampened with turpentine will help remove the stubborn areas, it also helps to stop that muddy look that you can get with such grain fillers. As someone stated earlier that look is more to do with not removing the excess thoroughly enough.


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PostPosted: Wed Feb 06, 2019 7:24 pm 
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Brazilian Rosewood
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Joined: Wed Feb 20, 2008 9:12 pm
Posts: 6983
First name: Mike
Last Name: O'Melia
City: Huntsville
State: Alabama
Focus: Build
Status: Semi-pro
bcombs510 wrote:
Mike, are you scuff sanding the adhesion promoter before spraying finish on it? You have to with UV cured, not sure about others.

Also, FWIW, I'm really enjoying working with the UV cure porefill gel. Very easy to apply and levels nicely.

Yes

I really want to go UV. Thats next


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PostPosted: Wed Feb 06, 2019 7:27 pm 
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Brazilian Rosewood
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J De Rocher wrote:
Mike OMelia wrote:
No question that epoxy is a mess to work with. I totally underestimated the effort. It almost caused me to quit it. I think anybody attempting this needs to understand a first attempt will likely be a failure. Sand it back, use an epoxy stripper (good luck finding that these days) and try again. there is nothing about this that is easy peazy first time out.


I'm sorry, but I have to disagree with this just so that anyone considering using epoxy for the first time doesn't get totally spooked. I don't find it a mess to work with at all and it worked great for me on the first try. It mixes easily, it applies nicely with the squeegee-like device of your choice (or a gloved finger for the neck), it takes very little of it to cover the back, sides, and neck, it has a good working time, and it sands and scrapes very nicely.

I'm wondering why an epoxy stripper would be needed to remove it?

In another thread, you said that you use sealer/adhesion promoter beneath z-poxy to minimize wood oil flow. I haven't used cocobolo yet, but I haven't seen problems with with z-poxy and Indian rosewood, bubinga, or ziricote which are oily woods (the clogging of my drum sander sandpaper confirms that). Have you seen wood oils get through z-poxy?

...



On oily woods, zpoxy picks up oils, mixes with epoxy, and then can darken light sap wood and bindings. anybody who has used epoxy on oily woods can attest to this.


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PostPosted: Wed Feb 06, 2019 7:35 pm 
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Brazilian Rosewood
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The secret sauce is in the Etorre Squeegee. I usually buy the 12-18" wide ones, cut them to 6". Cheap cheap cheap. They will last several guitars. Wash with DNA. Get them at any big box store. I use Caruth scraper on big drips and ridges, razor blade (rounded corners, tape on ends) on finer issues. Grind the epoxy into the pores. For me, the final piece of the puzzle was the highly diluted wash coat and the adhesion promoter.


Last edited by Mike OMelia on Wed Feb 06, 2019 7:36 pm, edited 1 time in total.

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PostPosted: Wed Feb 06, 2019 7:36 pm 
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Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
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Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
I found that oil-based paste wood pore filler works a lot better if I do a seal coat first.


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PostPosted: Wed Feb 06, 2019 10:59 pm 
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First name: Jay
Last Name: De Rocher
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Mike OMelia wrote:
On oily woods, zpoxy picks up oils, mixes with epoxy, and then can darken light sap wood and bindings. anybody who has used epoxy on oily woods can attest to this.


I cannot attest to that based on my own experience. For example, these two guitars below. Z-poxy was applied directly to bare wood, bindings, and white purfling with no bleed in either case. The top one is Indian rosewood with koa binding and the bottom is Indian rosewood with cocobolo binding. There was no discernible bleed from the rosewood to the koa and in both cases the white purfling was unaffected and remained completely white.

The rosewood sets on these two were oily and the cocobolo binding was definitely oily cocobolo. I've also done two guitars that have bloodwood binding (which bleeds) next to white purfling and had no problem. It seems that there must be some difference somewhere in the methods that we use that would account for the different experiences. I wonder what it would be.

Attachment:
Indian rosewood - koa binding.jpg

Attachment:
Indian rosewood - cocobolo.jpg


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PostPosted: Thu Feb 07, 2019 12:12 am 
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Brazilian Rosewood
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Joined: Tue May 13, 2008 10:44 am
Posts: 6256
Location: Virginia
Nice examples Jay, beautiful lines on those ones.



These users thanked the author jfmckenna for the post: J De Rocher (Thu Feb 07, 2019 2:11 am)
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PostPosted: Thu Feb 07, 2019 6:29 pm 
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Brazilian Rosewood
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All I can say is the next time you use zpoxy on an oily wood, take a picture of the epoxy residue that you scrape off. I never saw this problem (as bad) with EIR. But when I did lots of African Blackwood and Cocobolo bodies, def saw it. Run a strip each of coco, EIR, and African Blackwood through a drum sander with 80 grit paper. Tell me what u see. There is oily wood, then there is REALLY oily wood.
(nice work by the way!)


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PostPosted: Thu Feb 07, 2019 8:32 pm 
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First name: Jay
Last Name: De Rocher
City: Bothell
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I think this discussion is helpful. What I would like to understand is why you've seen bleeding with epoxy on oily woods and I haven't. Maybe I haven't seen it because I haven't built a guitar with cocobolo back and sides yet and I might very well see bleeding when I get around to using one of the sets I have. Based on your experience with cocobolo, I will definitely do testing on scrap before go ahead with the pore filling on a cocobolo guitar. That still doesn't explain the different experiences with Indian rosewood and my not having problems with bloodwood. Maybe some minor difference in technique somewhere? I don't know.

One thing I've learned over the years is that if a procedure is meant to work under worst-case conditions, it can include steps that are not needed under less than worst-case conditions. I have an aversion to including steps in a procedure if in fact they are not actually needed. It's not useful to make a procedure longer or more complicated than it needs to be. On the other hand, it's good to at least be aware that the method that has worked for me on the woods I've used may not work well with woods that have even higher oil content. So reading about the ins and outs of different finishing procedures from discussions of other builders' experiences like this is valuable.

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PostPosted: Thu Feb 07, 2019 9:57 pm 
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Brazilian Rosewood
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Jay, ABW and Coco will def bleed under epoxy. Seeing this happen led me to find a good sealer.


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