Official Luthiers Forum!

I applied Z-poxy to my Cocobolo 000 body and neck last night, todayI have scraped and sanded the body back to wood and 90% of the grain is filled. I hope to get to the neck after supper. What a wonderful product, I have already cut several days off of the finishing time with one days work, I was never happy with my grain filling on the 1st 3 guitars, in fact if I sealed and started lacquering now I would be starting the finish on the best fill I have done, but will do the 2nd coat.

Thanks to the OLF and Hesh for the info on using this product. I will post a photo after the 2nd coat and sanding.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Fred, did you try the 50:50 wash? Hesh suggested that ratio (d-alcohol).

Works great. after doing that, its the only way I will apply in the future. Had no problems with cure time. Also, since you use a rag to apply, you minimize exposure (even though you are wearing gloves). You also save on product cause a little goes a long way.

Mike

You are very welcome Fred my friend.

While we are on the subject of using Z-Poxy I wanted to post some pics of a project that I am doing. I am taking Robbie O'Brien's French polish course and we had our first session last Sunday evening. Our assignment was to prep some test boards and this included pore filling what ever dark wood we wanted to use.

I choose EIRW because it's here, available, and this set looks like something that I would never build with anyway. Robbie showed us several methods of pore filling that included dust and shellac, LMI water based filler, and LMI paste filler. He was able to get a complete fill with all methods right before our eyes. We were given the option to use epoxy and since I am in the class to improve my French polish chops and not to learn to pore fill I wanted to use something that I always get decent results with so I used Z-Poxy.

Here are my test boards:



This is how the EIRW looked before two applications of Z-Poxy 6 hours apart which means that I was able to completely pore fill this test board including cure time in 12 hours or one day.



For this test board I wanted to sand back to the wood and only leave the epoxy in the pores. As you can see the epoxy darkens the pores several shades darker than the wood which I think looks pretty cool and adds character as Robbie says. The pores are 100% filled and I am not using a 50:50 wash coat on this one because I want to only see the French polish finish when done.

I sanded the epoxy back with my ROS set on 1/2 it's aggressiveness/speed potential and 220 paper. The epoxy stays in the pores fine even when using a ROS and 6 hours of cure time. The temp in my shop is around 75F and the RH is close to 45%. My final sanding since I am going to FP this was with 320 on a foam block and with the grain.



Anyway thanks for looking and if you get a chance to take one of Robbie's on-line courses they are highly recommended. I don't know that I will ever French polish a guitar again but this is something that I wanted to get better at and I can think of no finer teacher than Robbie.

Lastly but very important epoxy pore filling does require some precautions for safety's sake and this method is not for everyone. Please be safe.

Thanks!

Hey Hesh!

Do you have a link for those courses?

_________________
Larry
Fox Haven Lutherie

Hey Larry I don't have a link but I am sure Robbie O'Brien can help you. Robbie is a member here so just PM him (his OLF screen name is also "Robbie O'Brien") and he will be happy to help you out.

First coat scraped and sanded out well and the 2nd application is curing, so I worked on my Wedge guitar top and back bracing. I really like the look of the epoxy on Cocobolo and the mahogany neck but the neck will need to be stained as the color and grain of the attached headstock ears is too different looking with only a clear finish. If I wash coat the body and smooth sand will I have any issues with the vinyl sealer and nitro lacquer sticking. My original plan was to sand out to wood but the cocobolo just looks so good.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Heh Hesh - I got on a pore filling binge too.

No pictures here unfortunately, but I did do a wide range of tests in prep for Robbie's FP session tomorrow. I was working with two wood samples and did both sides of each:

Walnut: Side one: Z-Poxy, two coats, sanded back to wood at 400 grit. Two coats filled completely, one did not.

Side two: Behlen's Pore-O-Pac oil-based grain filler, Walnut color. This went on like the oil-based filler that Robbie used, and
filled in one session. I was truly impressed. I did not like the darker color of the wood afterwards, though. The wood sample
prepped for FP is much darker than the Z-Poxy'd side.

Padauk: Warning - this has pores like craters. Most interested in this experiment as I'm working on a padauk box for a dread right now.

Side one: Z-Poxy, two coats, sanded and then a 50:50 wash applied. The Z-Poxy worked fine with two coats. Editorial comment -
this test explains perfectly why people would like to work with the 50:50 wash coat of Z-Poxy rather than sanding back to wood. The
wood is gorgeous! I had no idea, I had never used Padauk for anything before. It just shimmers under the Z-Poxy wash coat. I wish
the epoxy would stand up to UV - I'd be done finishing.

Side two: Crystalac. This is a water-based microbead product, probably similar to the microbead filler sold by LMI. It is easy to apply
and can be sanded very soon after application. I did not get a complete fill after two coats. Third to come this evening. I've used
this a number of times before under both nitro and KTM-9 and it works well with both. It doesn't have any special properties that I
can see in terms of improving the wood appearance.

_________________
Jim Kirby
kirby@udel.edu

I am a little confused about the "wash coat". I assume you are porefilling as usual with one normal coat of epoxy. Then you sand back to the wood (and repeat as necessary).

Are you then doing a wash coat of 50/50 AFTER sanding back to wood? Then what? Do you shoot finish right over the wash coat, or do you sand that as well?

Thanks,

rlrhett the wash coat is a final coat and optional. It is used when you want to leave a thin epoxy film on the surface of the wood and have sanded back too far in spots say after the second epoxy pore filling coat. By wiping on the wash coat it applies a thin epoxy film on the surface and evens out the color of the wood.

If you have not used epoxy for pore filling you wouldn't know this but epoxy "pops" the figure and color of wood very well. Some have even pondered if epoxy could be used as a finish but it is too soft for that.

After the pores are completely filled I have sprayed lacquer directly on the epoxy with no problems some years later now. But what I would recommend is to spray a seal coat of shellac first and then go to lacquer if that is what you are using as a finish.

Also keep in mind that shellac sticks to epoxy very well as it seems to stick to anything..... but epoxy may have adhesion problems if applied to a shellac surface.

Remember too that you can sand back to the wood when using epoxy as a pore filler and leave it only in the pores. There is a very slight amber tint to epoxy and sometimes, depending on what we will be finishing with ultimately, the amber tint is not desirable.

Second epoxy coat sanded back to wood and there is not a single grain pore or other low spot showing, I have never had this kind of results with pore fillers.

I must decide if I will do a wipe coat or just seal and spray the lacquer, Hesh mentioned shellac over the epoxy, I have always ( 3 times ) used vinyl sealer, is shellac a better sealer or is vinyl sealer just as good?

Fred
With tender shoulder from sanding.

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Fred, if you see no pore issues, move on to the shellac. Seriously. In the future, I will do a squeegee app of the epoxy, then a wash app (after sanding back to wood). Then 2 shellacs. If I see any nefarious pores, then (as Rod True) suggested, apply medium viscosity (or thick? I used gap filler) CA on the unsanded shellac. Sand, then maybe one more CA an 2 shellacs. Hesh and others have warned against epoxy over shellac, so CA is a good repair. This sounds like a lot of material mixing, but so far I have had good results. I think Rod likes CA as his only pore filler (no epoxy). But the expoxy seems to be an excellent wood hardener. I'm a newbie, so experiment at risk and get more advice.

Mike

I did some z-poxy-ing too on the weekend.

I did the fill and wash coat then laid on 2 coats of varnish.

Now I am seeing a few pore areas I'd like to fill some more.

Can I hit that with more Z-Poxy?

Neil

Neil,

I do not know this for a fact, but Hesh said no epoxy over shellac. Not sure about varnish (is not that a catchall phrase?)

After z-poxy and 2 shellacs, I used CA. I can now count the number of pores that are showing (after 3 coats of EmTech. Gonna fix one at a time with CA (so long as no chimes in says CA over Emtech is a bad idea)

Mike

If the pores are not huge, and i have some finish on already, i drop fill with the actuall finish. Less messy and problematic than making a multilayered finish sandwich.

_________________
Jordan Aceto
Ithaca, NY

The Z-poxy filled guitar now has the 1st coats on Nitro sprayed over the vinyl sealer and not a pore is showing. I will need to drop fill a couple spots along the binding and after the 1st leveling it will look great. I will do one more 4 coat spraying and another leveling and should hit the final coats early next week. The hard part will be waiting 3 or 4 weeks before final sanding and buffing. At least I have the wedge guitar to keep me busy while I wait.

As I said in the subject, thanks to OLF and Hesh for turning on to Z-poxy, finishing has become enjoyable.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Way-to-go Fred my friend - sounds like you are doing great!