Filling cracks in exterior wood: What to use?
 

On Tuesday, July 29, 1997 3:00:00 AM UTC-4, wrote:
In article 01bc9bb9$eb473a20$6072d9ce@casey-s-acer,
"Casey " wrote:

Hi Gary.
The reason that other fillers fail is this - the wood gets wet, and the
fillers let go.
So: dry out everything to be filled. Cover it with plastic when it rains,
then let it get aired out when the weather is fair.
Then: make sure it cannot absorb water anymore. I use Abatron's wood epoxy
system. I restore historic woodwork with this stuff, and it can work
wonders. The liquid epoxy seals,waterproofs, and consolidates rotted wood,
too. Then the Abatron filler, which has the same coefficient of expansion
as wood, is used to fill any gaps. It is considered structural (in
compression) and can be used to rebuild load-bearing columns.
Wood thus repaired will no longer be subject to deterioration.
I don't work for Abatron, I just use it. I think they have a website at
www.abatron.com
Casey

Gary Dyrkacz wrote in article
...
Hi:

This is actually a couple of related gap filling problems in exterior
wood. In one of my exterior wooden sills I have a several splits
along the grain. These areas tend to be the first place that paint
begins to weather away. The gaps are about 1/16" wide. What can I
use for filler on exterior wood cracks that will weather well? It is
not simple to replace the entire sill.

I have a similiar filling problem in window trim that was rotting
away. I replaced several sections, but have some gaps that are 1/8 to
3/16" wide at a couple of butt joints. Again, what can I use? How
about Bondo or a similar filler?

Thanks for any help.
-
Gary Dyrkacz

Learn about Radio Control Aircraft
http://www.mcs.net/~dyrgcmn/
-


Gary: Casey's analysis of your problem is essentially correct. I can only
add that you--and Casey too--take a look at the Clear Penetrating Epoxy
Sealer at http:// www.rotdoctor.com/ These are wood derived resins and
epoxy and epoxy putty products that have been stringently tested in a
marine environment. I can't comment on the Arbitron product; we have some
on order for testing. John

-------------------==== Posted via Deja News ====-----------------------
http://www.dejanews.com/ Search, Read, Post to Usenet

Clear penetrating epoxy is just over priced, thinned epoxy. Do a little more research.

Get ordinary two part epoxy. The best prices I have found at at US Composites on the web. If you are trying to fix soft wood or want to achieve extra wood penetration add up to 10% denatured alcohol. You've just made "clear penetrating epoxy" for about 1/4 the price. Alcohol will thin the epoxy and does not inhibit curing. Denatured alcohol is cheap in quarts from lowes or home depot. It cleans up uncured epoxy as well so you get two uses from it. You can also use acetone for both but it's more expensive and more toxic.

For fillers I also use two part epoxy mixed with something to thicken it. Microspheres is pretty common for this and is very light and reasonably priced. A paste made from microspheres and epoxy doesn't sag much if you can't lay the surface down flat. It also sands easier. But for filling wood you can also use ordinary sawdust as a thickener. As well as chopped fiberglass and talc, baby powder.

Unlike polyester resins, it's rather hard to prevent epoxy from curing and it's binds very well when cured. It also resists just about everything when cured. Just be wary of anything called epoxy that is not in two parts. It's not really epoxy if you don't have to mix it.