Large gap filler material?

[Warthog]

I am trying to fill the gaps between 38mm outboard motor tubes and the 5.38inch diameter body tube and wings that they are attached to. It is an upscale of the LOC Starfighter. The gaps are too big to fill with epoxy (even with microballoons).

I am thinking about cutting insulation foam board, fitting it into the gaps and leaving room for a layer of epoxy (maybe 1/8 inch thick) over the foam to bond to the motor tubes and the wing or body.

I considered chopped fiberglass cloth mixed with epoxy but I think that the surfaces to be painted would be really rough and would require a lot of filling to get smooth.

The best solution would be something pourable that would self level, bond well and be flexible enough to handle stress without cracking. (sounds like epoxy, doesn't it?)

Any ideas?

Thanks

 

[rstaff3]

Do you want the whole length filled or just plug the ends? If the latter, a light epoxy filler like SuperFil would work. Or, maybe a quirt of expanding foam, just a squirt, them backfill with epoxy to get a better finish.

If you need support, could you epoxy in a dowel of the right diameter and then plug the ends as above.

Just thinking out loud.

Or are you talking fillet-like filling?

 

[falingtrea]

I have used wood glue and toilet paper before, making a paper mache type substance to fill gaps in model rockets. Kinad messy though.

 

[roadkill]

Centering rings....

 

[Johnnie]

I am trying to fill the gaps between 38mm outboard motor tubes and the 5.38inch diameter body tube and wings that they are attached to. It is an upscale of the LOC Starfighter. The gaps are too big to fill with epoxy (even with microballoons).

I am thinking about cutting insulation foam board, fitting it into the gaps and leaving room for a layer of epoxy (maybe 1/8 inch thick) over the foam to bond to the motor tubes and the wing or body.

I considered chopped fiberglass cloth mixed with epoxy but I think that the surfaces to be painted would be really rough and would require a lot of filling to get smooth.

The best solution would be something pourable that would self level, bond well and be flexible enough to handle stress without cracking. (sounds like epoxy, doesn't it?)

Any ideas?

Thanks

Pictures of your dilema please...?

Johnnie

 

[Warthog]

I will put up a picture. Someone has suggested PML's pourable expanding foam. That may be the ticket. Some practice will be needed. I used it before and ended up with a pretty big glob o' foam. (didn't believe the instructions.....duh!!!)

 

[Pantherjon]

You could also lay down a thin strip of Gorilla Glue and a couple of drops of water to make it foam and expand..And you could probably shape it as it cures...