What can you use wood filler over?

So, my attempt to make finishing homemade paper tube easier by slipping a single layer printed sleeve over and filling the lines with thinned epoxy was only a partial success.

In places is looks great, and in places it’s rather lumpy.

Can I use wood filler over sanded epoxy, or do I have to use something else?

My guess is that after priming, Bondo Spot and Glazing putty might be a better choice. CWF might work over primer but I am not sure.

...I have used a few different wood fillers (and bondo) over epoxy. Haven't come across a product that didn't bond to the epoxy.

Just make sure surface prep is good. Sanded and the cleaned of all dust. I have used this bondo over rocketpoxy, Hysol, 5 minute, primer, bare wood and glass. This will sand to a smooth finish where as if you get the long fiber stuff, it will not.

Bondo glazing putty worked fine. Though it would have better pre-primer. The tube of putty isn’t evenly mixed, and it gets too thin it lifts the Rusto 2X.

The lifting effect on the Rusto 2X is because the Bondo S&G Putty is a high solids lacquer based filler, if put over a lacquer base primer, no issues, when put over enamel primers it eats the primer.

rharshberger said:

The lifting effect on the Rusto 2X is because the Bondo S&G Putty is a high solids lacquer based filler, if put over a lacquer base primer, no issues, when put over enamel primers it eats the primer.

Click to expand...

I figured as much. It only seems to be a problem if the putty squeezes out runny. If it's more like toothpaste, then it spreads on without issue.
The primer/putty blend is harder to sand than the putty alone. By a lot. It seems to have a really short working time compared to CWF. Put a spot or short line down, spread it with a smooth motion. Don't fuss with it - too thin, repeat later. Too thick, sand off.

The new primer laid down well. I've just got a couple little areas where I missed refilling bondo shrinkage. I'm thinking that tells me I put it down too thick in spots. Well, it's first time I used it, and what do you know - I learned something.

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