Tom Verstappen

Hi,

How many layers do you use when you make a plug (mold)?
What weight of glass do you use?

Tom

hayman

I kind of remembering hearing somewhere that a rule of thumb is the mold lay-up should be 6 times thicker then the part lay-up. if you use a surface coat the overall thickness will vary. I kind of decide based on the size of the part being molded.

Bill
http://www.paonline.com/hayman/video.htm

Mike James

My opinion is that molds simply need to be thick enough to be rigid and durable, whatever their size. For most molds I've made, (.60 size fuselages and larger) this means the mold should ideally be about 1/4 to 1/2 inch thick.

That assumes that you want them to last for a while. If you're only going to make a few parts, you could get by with a thinner mold.

Also, if you find that your molds aren't thick enough to be rigid, it would be a simple matter to go back later and add more reinforcement.

hayman

Also, if you find that your molds aren't thick enough to be rigid, it would be a simple matter to go back later and add more reinforcement. [/B][/QUOTE]


I have also sandwiched a layer of end grain balsa for a wing mold I made to add thickness and to prevent twist.

Bill
http://www.paonline.com/hayman/video.htm

yakman

I use sawdust after a few layers of chop strand for rigidity. Very cheap! I scoop it off the floor.

Tom Verstappen

Hi Mike,

What weight of glass do you use?
Do you use for the first layer a thinner cloth then for the next layers?

Thanks
Tom