Shaping Foam

[biggsgolf]

What is tge best way to shape foam to match the hull curve?

[Bob Gato]

I don't know if you can adapt this method to what you are trying to cut but I use aluminum building .005" flashing for forms to follow with a hotwire (easily made from a lighting dimmer and a doorbell transformer and some ss wire) If the forms don't work for you- you can freehand cut-clean and easy...these two pages show my making of two CRRCs for my Navy Seal SOC...I've made several masters for fiberglass hulls using this method-it not only cuts the foam -it cuts time!

https://www.rcgroups.com/forums/show...&postcount=217

https://www.rcgroups.com/forums/showpost.php?p=41032455&postcount=218

[Bob Gato]

Sorry-that last link didn't work out-so I opted to go the additional post as I was surely out of edits!

https://www.rcgroups.com/forums/show...&postcount=218

[biggsgolf]

I am referring to flotation trimming foam at the waterline which is placed oh the curved lower hull

[RCSubGuy]

I simply use a band saw and then sand to shape. Works like a champ!

Bob

[biggsgolf]

That sounds good!

[coryhenry]

I agree I just sand, it goes really quickly.

[biggsgolf]

Thanks guys

[trout]

I learned to put vertical cuts in my foam to allow air trapped between the foam and hull to escape. I had a sub that would trim correctly, but if I waited awhile and came back to it, it would be sitting lower in the water. The best theory I could come up with is trapped air. David recommended putting channels in to allow any trapped air to escape.

[biggsgolf]

I totally love that you brought that up. I have noticed that my first sub would be perfectly trimmed, but would change, perhaps ghis is why.

[Bob Gato]

Just throwing this out there-there is foam and there is foam-some is closed cell and some is open cell otherwise known as a sponge ..I don't really know what you are using-but stay away from the white polyurethane shipping foam. Your best bet is pink or green styrene construction foam from big box home stores...

[biggsgolf]

Yes, I use the green closed cell, thx for bringing it up,

[trout]

Mine is the closed cell pink stuff, good point Bob!