Updated Epoxy Pore Filling Demo - Video

[Allen]

A new video I shot to demo using epoxy resin filling a mahogany baritone ukulele. Some might find it useful.


youtu.be/f1zt0g7oYXM

[asgilbert]

Great video Allen. Thank you for sharing it with us.

[56nortondomy]

Thanks Allen that's really helpful.
Wayne

[kiwigeo]

Thanks Allen, Questions:

1) which epoxy resin are you using? West Systems or Boatcote?
2) after the initial epoxy sessions do you do any sanding back?

[Allen]

I switched to BoatCoat several years ago and would never go back to WEST Systems.

For the first application I use their TPRDA thinning additive that really allows the resin to penetrate into the timber and get to the bottom of the pores. As I'm always building more than one instrument at a time, I will apply epoxy to one a little heavy, then go onto another instrument. Come back to the first and that resin will have sucked into the timber. I apply some more and work it into the timber and clean it up as in this video.

I sand back with P220 between reapplications. In my environment I can sometimes get a coat on in the morning and another in the late afternoon. But more often than not its just better to plan on overnight cure. If cooler than 20C you would want 24 hours.

It sands very well. Not gummy and no amines to worry about causing adhesion problems with your finish.

[Bob_H]

Hi Allen - sorry to revive an old thread - I note you comment that you sand back with 220 grit after the initial application - can you advise what you do after further applications, and between the final application and moving on to applying a finish? I am just about to attempt pore sealing on a lacy sheoak baritone, using Bote Cote for the first time. Thanks (and a Merry New Year to you!)

[Allen]

Same for for all subsiquent coats as required.

For softwood soundboards that don't get pore filled I will sand up to P320 with my Festool fine orbit sander. It gives an effective finish as if you were going P400 by hand.

[Bob_H]

Thanks!

[kiwigeo]

Thanks for the update Allen. Each time you sand back are you going back to bare wood and leaving the epoxy just in the pores or are you aiming to leave an overall even layer of epoxy on both pores and wood?

[Allen]

I never leave a "layer" of epoxy. But it's a fine line of sanding so you are just leaving it in the pores or cutting timber off and exposing more pores.

[Bob_H]

I never leave a "layer" of epoxy. But it's a fine line of sanding so you are just leaving it in the pores or cutting timber off and exposing more pores.

It's fascinating to see the differences in approaches - Gore and Gillet talk about trying to not only fill the grain but to leave a very thin continuous coating of epoxy, which is subsequently "over-coated". You all achieve fantastic results, so clearly many ways to skin that cat!

[EliGuitars]

I switched to BoatCoat several years ago and would never go back to WEST Systems.

I.
Sorry for the post digging.
I'm starting to use epoxy. Meanwhile testing in some scrap pieces..
Why not West Systems? And why Boatcoat?


My approach in my testing so far with some promising results is the 205 hardner and 405 epoxy (West Sytems) much like Ken Parker (archtop). Not quite a pore filling... I apply a thin coat than "rinse it" as much as I can. Let it cure 24 to 48h. Then I apply linseed oli (4 or 5 coats), more for a glossy finish.

Do you get better/nice results with the use of pore filling or do you think that the Ken Parker way is better/easy....

Thanks!

[Allen]

WEST Systems is extremly sensitive to under or over use of their catalyst, so when making small batches it's very easy to stuff that up. I make up 10 grams at a time.

Also the amine blush you get from WEST Systems can be very problematic causing adheshion problems with your top coats.

Bote Cote is dead easy to mix in small batches. No amine blush problem ever. Far easier to sand. And it's made in Brisbane. Dead easy to purchase where WEST Systems is only available to select distributors and not available in Cairns whereas Bote Cote is stocked locally.

No idea what Ken Parker does. My system alows me to go from pore fill to final buff high gloss within 5 days if I want. I'm never in that much of a rush as I have a minimum of 3 unstruments being built at the same pace, so it's usually 10 days.

Have a look in the Gallery section at some of my instruments and judge for yourself on the results.

[kiwigeo]

Ken Parker is using a varnish top coat over a layer of epoxy....he explains it all here: https://kenparkerarchtops.com/etude-applying-finish