Help ... filling a hole with resin .. someone did this w a P-51 belly ...

[Gary F]

  I've got a largish hole to fill and was thinking of trying to do it with resin, as I seem to recall someone (Wolfik??) doing this to the belly of a P-51 after cutting off the radiator intake area.  If you're out there, or if you've used this technique, could you run me through it again? 
  Ie, how did you mask off the opening (tape, paper?) and did you have to do anything to help dissipate the heat from the resin setting up?
  Also, did the resin plug fuse to the plastic or did it need some CA glue to reinforce the plug sticking to the kit part?
  My project involves a 48th scale F-8 having the large refueling bulge removed from the left fuselage side near the pit area ... need to fill in that large hole and thought this way might work but couldn't recall some of the details ..

thanks,
Gary F

[cthulhu77]

I would say plastic sheeting to back it up, and use glazing putty. Hot resin is going to warp your styrene.

[Ed S]

Definitely put a piece of styrene behind the hole.  You'll need a lot less filler.  I would suggest some two-part epoxy putty (Milliput, Apoxy, etc.).  It is easy to work with, doesn't get very warm and it doesn't shrink or crack as it cures. 

Ed

[Chap]

Gary, I believe this is what you were referring to. Twin-Stang

~Steve

[John Howling Mouse]

When I removed the ventral scoop on my Mustang for the  Sentinel , I simply filled it in with plastic sheet.
I determined the exact aperture of the cut void using my simple technique of tracing the edge of the aperture onto clear tape which had been applied over the void.

Same would work on a curved surface: simply bend the plastic sheet to match the contour around the cut-out void.

If you want to use resin, that will work too.  I often use Smooth-On or Alumalite products for filling in wingroots, etc.
I've never had polyurethanes or resins warp the plastic on quality model kits.  Even though such resins are endothermic when mixed, you'd have to use quite a bit of mixed volume to get the temperature high enough to warp all but the very thinnest/lowest quality styrene kits.

[Jeffry Fontaine]

I would have thought that this would be an opportunity for you to try out that foam core poster board called Sintra or Forex.  It would be ideal for what you have in mind if you take the time to trace out the opening as described by Barry.

[Gary F]

Thanks Chap and JHM ... that's the build I was thinking about.  Glad to hear someone else (JHM) uses resin that way with success.  Think I will give it a try on my Crusader.  Tape over the opening from the outside and pour from the inside ... here's hoping!

Gary F

[Gary F]

Well, I tried it and it worked just fine.  I did as mentioned and taped over the opening from the outside then poured the resin from the inside, let it set up, then removed the tape.  Needs a quick touch with some 600 sandpaper and it will be just fine.
  Since it worked okay, pulled out another F-8 and poured resin into the cavity behind the refueling bulge (with the bulge still on) and will just sand down the area til flat and compare the 2 methods, but either way, no problems because of heat or such.
  Got some pics but can't get them into the computer at the moment ... had a hard drive failure last month and seems I haven't put the camera software back onto the computer yet ... gotta find the disc first ...

Gary F