davbow

My Feedback: (6)

Hi all, i just made a mold of my F16's intake duct as it was damaged in a crash. i rebuilt the intake duct with the remaining foam then glassed over it. it cured and i peeled it away from the foam and it is flimsy. i used boat fiberglass repair kit made by bondo. i thought i would have a hard shell that would not bend.

tommyboy1229

Need more information. What weight cloth did you use? How many layers?


Tom

Ed Smith

This is with out seeing precisely what you have. If possible a mold should have the female form with a flange around it. I am guessing you have a female mold without a flange, in other words a strange shape bowl. The "Bowl" should be at least 1/16 thick. cloth and resin. Around the top of the opening on the outside the thickness should be built up to about 1/8 thick for 1" deep. The easiest way to build up thickness is with fibreglass mat, not cloth.

If you intend to do this then put the mold back on the plug before building up the thickness.

Ed S

WORNBOOTS

My Feedback: (33)

Understanding that you are saying the part came out flimsy? other than the comments above I wold also check the amount of activator you used. Did it take a long time to set and cure?
I just used Bondo brand Polyester resin for the first time on a cowl I reproduced and I was not thrilled with it at first, but my second attempt was much better after playing withe the ratio. Used two layers of 6 oz. cloth and only 5 drops per and it set and cured well and was rigid enough to carve on and only a slight flexing.