Grain Filling Large Pore Woods

 

by: Jeff Miller

used with permission

 

 

 

If you're not familiar with grain filling, this is something you need to do on wood with large pores if you want it to look like glass when you're done. If you don't fill the grain, you will have large pits in the finish. Types of wood that need to be filled are rosewood, mahogany, korina (limba), ash and walnut. There are others, but these are probably the most encountered in guitar building. You don't need to fill maple or alder because they are tighter grained woods (small pores).

 

 

 

Visit Jeff on his site at GuitaristJeffMiller.com

 

 

 

 

 

 

 

 

 

I'm using epoxy for the grain filler. The reason I use epoxy is because it doesn't color the wood and it doesn't make the pores a different color like some oil based fillers I tried. That was probably my fault, but I just couldn't get oil based fillers to work right. Epoxy fills up the pores in a couple applications and it leaves the wood looking natural IMHO. I use the 5 minute stuff you get a Lowes. When I mix it up, I thin it just a little with denatured alcohol. I use a plastic auto body filler spreader and scrape it across the grain filling the pores. After I pack it into all the pores, I wipe off any excess with a rag dipped in alcohol. Make sure to wear rubber gloves and keep a rag dampened in alcohol ready. You can become a sticky mess real quick if you're not careful. Practice on scrap first.

 

 

 

 

 

 

 

 

 

 

Here I've done a couple coats of epoxy. Once it hardens, I'll just scuff it with 320 sandpaper and it'll be ready. I want to leave the epoxy just in the pores and not on the top of the wood. If you leave too much on, it will show as light and dark places in the finish. Use naptha to check for light and dark places. You can gently scrape your fingernail across the grain to check if the pores are filled. If it feels rough with your fingernail, you need to fill more. You want it to feel like you are running your fingernail across a piece of glass.

 

Jeff uses the Devcon 5 Minute Epoxy although he does not endorse the product.