Pore o pac not filling?

The Achilles' Heel of Luthiery
Post Reply
Jcolvin
Posts: 72
Joined: Tue Jan 28, 2014 3:07 pm

Pore o pac not filling?

Post by Jcolvin »

Hello all,

This is my first attempt at pore filling with a paste filler. On my first build I finished with Tru oil and pore filled by slurry sanding with the tru oil. It worked but took many many sessions. For this build I got some pore o pac hoping to speed up the pore filling and get a smoother end result. Here's what I've done:

-wash coat of 1lb cut shellac
-light dry sand with 400 (this made the pores show up very clearly as they remained glossy but the surface was sanded)
-pore o pac- I mixed it up thoroughly, wiped it on with a rag going in circles, and against the grain (in that order), leaving a pretty thick layer. Then waited maybe ten minutes and squeegeed it off with a credit card at a 45 degree angle. Wipe with a clean rag across the grain to clean it up a bit more. Let dry over night.
-repeated the pore o pac process two more times for a total of three applications.

The pores are still not filled as you can see in the photo. Am I doing something wrong or will it just take a few more applications?

Thanks!
You do not have the required permissions to view the files attached to this post.
tippie53
Posts: 7013
Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
Contact:

Re: Pore o pac not filling?

Post by tippie53 »

the 400 grit is not a good thing you don't want to sand much past 180.

First off you don't wipe it on you have to allow a certain amount of "flash" time.

What I do is first seal the box, then I mix my filler in a small container , I do about 3 tablespoons at a time. I get the natural so I have to stain it. After I color it I may thin it as when I mix it I want to see about the color of hershey chocolate syrup and about the same consistency . Once I have it mixed and thinned I then add a drop of naphtha for each tablespoon I used . This aids in the flash time.
With you rubbing it with a rag you never let it set up , the wiping didn't do much good.

So now you take this material and paint it on doing a side at a time , and the back so you are doing 3 separate fills. Allow the material to start to dry , this will go from what appears wet , to a color not unlike a chocolate bar , you can actually see the surface change when it gets to the flash or start drying point.
Now you start to rub it in. You will see little balls of material form and this is what you are working into the pores. You will do this about 2 to 3 times , and no need to sand between applications. When you are done a rub with steel wool or a scotch pad is all you need.
Then you seal this and start your finish cycle.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Jcolvin
Posts: 72
Joined: Tue Jan 28, 2014 3:07 pm

Re: Pore o pac not filling?

Post by Jcolvin »

Ahh ok thanks John! I'll give it another go.
Jcolvin
Posts: 72
Joined: Tue Jan 28, 2014 3:07 pm

Re: Pore o pac not filling?

Post by Jcolvin »

It seems to have worked better this time. Two applications with that method did the trick. Thanks again!
tippie53
Posts: 7013
Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
Contact:

Re: Pore o pac not filling?

Post by tippie53 »

glad to help
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Post Reply