Regular and Stainable Carpenter's Wood Filler Duel!

[hcmbanjo]

I remember reading a post where someone recommended the Stainable Wood Filler over the regular Carpenter's Wood Filler. After some questions had come up recently, I decided to compare the two, side by side.

I bought the Stainable Filler in a tube. I had a hard time getting it to squeeze out of the nozzle even after cutting off and enlarging the tip. I ended up slicing through the tube to get it all out.

For the rest of the article, I'll refer to the Carpenter's Wood Filler as CWF. The Stainable Wood Filler will be referred to as SWF.

I mixed it up with water as close as I could come to the regular CWF consistency. The SWF has wood fibers in it, at least that's what the tube advertised. When mixed, it's a little darker brown than the standard CWF.

I cut two pieces of 3/32" balsa from the same sheet for testing. The regular CWF brushed on with no problems. But the SWF went on very rough. It was not easy to get an even coat. In picture two both pieces are dry. You can easily see the differences in the two formulas. The darker filler is the SWF.

 

[hcmbanjo]

Sanding was another story.

Typically I use 400 grit to sand regular balsa filler.
I had to use 220 on the SWF to get it close to the surface. I then finish sanded the SWF piece with 400 grit. The balsa with the CWF sanded easily with just the 400 grit sandpaper.
The first picture on this post shows both sanded surfaces. You can still see the SWF piece is a little darker than the regular CWF piece. (Sorry the order of the balsa is flipped from the first post - the SWF is now on the left, the CWF is on the right.)

I have used stain on balsa in the past and then applied clear coat over the top. But I was concerned about the CWF sealing off the wood to where it wouldn't accept (absorb) a stain.
Some recent posts have talked about CWF sealing the balsa surface.

I was very surprised by the results. I picked out a Minwax Dark Walnut Stain. I applied stain evenly to both pieces. Check out the picture on the right -
There was no difference between the two! Both the CWF and the SWF accepted the stain. I can't really tell a differnce between the two pieces.

I won't be using the Stainable Wood Filler again! It was very hard to sand and while it does accept stain, the regular Carpenter's Wood Filler did too!

Both the CWF and the SWF only partially seal the wood. I've always understood a "Sealer" does what it's name implies. It seals out and closes off the surface from absorbing moisture. Both filler formulas are still water soluable afer they have dried.

 

[hcmbanjo]

Sorry, I've copied these posts to the Techniques section.
That's where it should have been in the first place!

 

[Gus]

Hans,

Really nice report. Your experience is similar to what Royatl spoke of.

The thread I think you're referncing can be read at: https://forums.rocketshoppe.com/showthread.php?t=4446&page=2&pp=10&highlight=wood+filler

I've put link from that thread to this one as well.

Really nice work.

Steve

 

[hcmbanjo]

Hi Gus,
It was interesting to read that thread again. I was referring to recent threads about CWF actually "sealing" the balsa suface.

I noticed you were using and preferred the Stainable Filler back then.
Maybe between then and now they've changed the formulations again. I had a hard time sanding the Stainable stuff to the surface.

 

[Mikus]

I had a hard time sanding the Stainable stuff to the surface.

Ooh I made the mistake of trying that stuff out and yah, I had a beast of a time sanding it down. I ended up throwing the rest out. :bangbang: