Filling in a roughed up belly on a belly lander airplane?

[PilotAndy1994]

Well I tried something cute today - I took the p-51 out on the snow, and surprisingly she took off just fine from the mix and flew just like she always did.
It wasn't until I decided the snow looked soft enough to try a belly skid that I ran into a problem.
The belly skid went perfect as planned - but what resulted was a CHEWED UP BELLY! Apparently I hit a rougher/icy patch and it didn't like it...

Anyone have any tips for how to fill in foam and then smooth it out?

I'd like to fill it in, and then paint back over it.

Learned a lesson today, though LOL:)LOL

[OV10]

Any of these should do ;)

https://www.motionrc.com/collections/finish-and-coatings

[Saltydawg]

Another good product for filling in dings, dents and scrapes is wood filler. It's fairly inexpensive and it sands easy.

[rifleman_btx]

I like the wood filler too. Does great

[F22trainer]

Even the vinyl spackle works great and it dries pretty quick.

[Pilotguy]

I have all 3 of what OV10 is pointing to. See photo. The one that works best for me is the “foam finish”(the one on the right in my pic). It came to me with just the right consistency and filled in my dings, dents, gouges and odd shaped holes with easy spreading and working it in with my fingers. The “foam filler” they sent me ( the one in the middle) is more difficult to spread, kneed and shape to match my dings, dents, gouges, odd shaped holes. It is more gooey or gummy but I don’t know if it’s supposed to be that way or not. Maybe so, otherwise what is the difference between the foam filler & the foam finish? The “Hobby Coat” (left I my pic), Is a liquid which I brushed on the edges of my wingtips & empennage (tail surfaces) to protect from scraping along the ground during ground loops.

[Skyboom]

Funny this thread popped up here. I was browsing YouTube earlier and stumbled on a product called Polycrylic. A fellow using fiberglass and Polycrylic applied it to his belly lander. Was thinking on doing the same. Lots of other good products I never thought of, in this thread as well. Thanks guys.

[brk6188]

I now use a 50/50 mix of lightweight spackle (Ace) and Durhams Water Paste for dents and grooves in my foam or balsa. Ratio can be changed -- 100% Durhams dries like rock. 100% spackle dries -- like spackle. Easy to sand but needs a coat of Poly to seal before painting. I tried the foam the model railroad guys use but found it to gummy. The "hobby" foam filler doesn't seem much different to spackle to me.

[crankestein]

Dollar tree sells the very light spackle, slow to dry, after a few hours sands easy to a smooth finish.

[RRHandy]

One thing I do for belly landers is take a 2L. bottle and cut it to shape and glue to the bottom for added strength and abrasion resistance. R.:Cool:

[Alpha]

In the past for belly landers in this approximate size/weight/landing speed, I've used adhesive non-skid tape. Go to your local hardware store and ask for the non-skid tape that's applied to stairs. They're available in various grits, like sandpaper, but have a strong adhesive on them. Light duty is more appropriate than the heavy duty, which is too thick and coarse for a small foamy plane. Even after they've worn out, the tape and backing will remain stuck to the foam fuselage. It's very durable and won't tear like the fiberglass-lined clear tape I used to use on flying wings. On a model the size of this Mustang I'd use the ones that feel closer to 220 grit sandpaper.

[F22trainer]

I have found those cheap lexan cutting surfaces - they’re like disposable cutting sheets for countertops - can be cut to the desired size and contact cemented to the belly. And they come in some useful colors!

[F22trainer]

CORRECTION...
I just realized I stated Lexan but they are polypropylene. I think you get like 6 in a pack at $store.

[F22trainer]

This was a polypropylene placemat I used On the Sophisticated Lady. The grainy texture took the contact cement really well. It’s pretty tough stuff!

[rifleman_btx]

Thats a hell of an idea, especially with yalls paved runway!

[fhhuber]

For fill in of abrasion damaged foam... I like to mix gorilla foaming poly glue with elmer's white or school glue. No no more than 10% or you start to get large air bubbles.
For gluing stuff together this works with up to 25% white glue. It sets up well and is strong. More than 25% white glue is not good.

You can use the original yellow foaming glue or the White fast setting (labeled dries white in the small packages)

Spread the mix into the holes and immediately cover with clear packing tape.
The tape can be left on as armor, or removed to allow a better finish when repainting. If you belly land fen, I recommend 3 layers of the packing tape.

The tape needs to be well stuck to the undamaged foam to prevent the foaming from pushing it up. If it does push up, you can pull tape and sand back to correct contour. Its mainly there to save you some work.

If you are going to need to sand/carve, there is a certain pint in the curing where its solid but easy to cut with a razor knife. The inside isn't very sticky to the knife but you can cut it or push on it and alter shape and the compressed foam will stay in place. (Don't over-press or you have a new divot to fill)

If you have silicone molds you can cast small foam parts with this method.