Hot Topics: Exterior Wood Filler Recommendation

A caulk gun against a weathered wood background.

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In attempting to repair a bad caulking job on an exterior window panel, this DIYer thinks he needs a different type of wood filler. The forum suggests, however, that while the previous method was poor, the product was actually right.

Original Post: Exterior Wood Filler Recommendation

jd thomas Member

I'm in need of an exterior wood filler to repair some damage. I haven't used Timbermate, but have seen a lot of people in love with it. It sounds like that would be perfect since it can be used as-is, as well as thinned for filling cracks and grain. However, apparently that is for interior use. Is there a similar product that is recommended for exterior use? I'm going to want to sand, prime, and paint after the repair. Would Famowood be best for me?

stickshift Group Moderator

What is it you're trying to fill?

marksr Forum Topic Moderator

Yeah, it would help to know just what you need to repair. If it's rot damage, that is best cut out and replaced.

jd thomas Member

It's actually not "damage" (don't know why I wrote that). I'm just redoing some outside corners on panels of a bay window. It looks like somebody previous to me filled the gaps between panels with some sort of caulk, and kind of smeared it all around in the process. It looks ugly so I want to take out the old caulk and refill those gaps with filler, sand them so they are neat, and then prime and paint.

ray2047 Group Moderator

Caulk might be easier and better. Caulk is easy to get right if after doing it you wait a few minutes and smooth and clean off excess with a damp sponge rinsed often in a bucket of water. Wood filler will tend to crack over time.

marksr Forum Topic Moderator

While a pic or two might change my mind, I agree with Ray that caulking would be best. There is a world of difference between a neat caulk job and a sloppy one. A damp rag/sponge is helpful in smoothing out the caulk and removing the excess from where it doesn't belong.

jd thomas Member

Thanks for the responses so far. Here are some pictures so you can see exactly what it is.

Here on we enjoy providing a place where home improvement novic

In attempting to repair a bad caulking job on an exterior window panel, this DIY

It just looks like a sloppy caulk job, right? To fix it, do I just need to sand away/pull out the old caulk and then re-caulk it neatly? The reason I ask about wood filler is that I see a lot of "caulk for inside corners, filler for outside corners." I guess I've got a mix of inside and outside corners needing attention here, so should I use caulk for the inside corners, and filler (Famowood?) for the outside corners, or just go with caulk for everything?

Any recommendations for exterior caulk products, by the way?

The sealing of the panels where they meet the brick is also a mess. Do I need a different type of caulk for that? Again, recommendations for a specific product if you can. Thanks.

Vermont Member

A few years ago, I tried a fiberglass auto body filler like Bondo on the exterior, and it seems to be holding well...but you have to plan your work so that you can apply it quickly once the catalyst is mixed. Besides being intended for car exteriors, it's also priced well below what I was paying for exterior plastic wood.

ray2047 Group Moderator

Latex caulks are usually a good choice. I don't recommend oil-based. I usually buy Dap.

marksr Forum Topic Moderator

Caulk doesn't sand well. I'd scrape off what I could first and then sand. Some folks shouldn't be allowed near a caulking gun. If the caulk had been expertly applied we wouldn't even be here. I also recommend latex caulk, specifically a siliconized acrylic latex caulk (it's paintable). A wet or damp rag/sponge is a good tool to both smooth out the caulk and remove unwanted excess.

jd thomas Member

Alright, thanks everybody. I'll get it cleaned up and fill gaps with White Lightning 3006, which is what I've been using for caulking anything lately, unless anyone has a better suggestion for an exterior caulk.

marksr Forum Topic Moderator

White Lightning is my preferred latex caulk.

To read the rest of the thread, check out the original post.