BP press

[MadMat]

I am in need of a new cylinder/pistons for pressing my BP. I was thinking of casting polyester resin "pistons" in a length of 2" PVC pipe so I will have a nice snug fit. Does anyone know of something I could use for a release agent to keep the resin from sticking to the I.D. of the pipe? (If only I had access to a lathe!)

[Col]

vaseline works well for pvc. i used it when i cast the internal stop ends on my new glue trough. I would use polyurethane casting resin for the piston, it wont shrink and its virtually indestructable once its cured.

Edited September 4, 2015 by Col

[MadMat]

Thanks for the info. I am basically using the polyester because I already have some. I do believe that the polyurethane would be better, but oh well, gonna make do with what I have. My biggest fear with a release agent like vaseline was that the solvents in the resin would attack it, but if it worked for you thats great to hear.

[mikeee]

Why not buy the 2" OD aluminum rod and heat the PVC pipe and slide it over the aluminum rod.

You can always add a layer of tape to the outside of the aluminum rod, when the PVC pipe cools

and shrinks around the aluminum rod after pressing the rod out of the PVC pipe you can remove

the layer of tape and the aluminum rod should fit inside the pipe with a little room to play with.

 

MadMat,

 

Where do you live, I have a metal lathe and can turn a 2" aluminum rod to any diameter you want.

[MadMat]

Thanks Mikee, the heated PVC pipe sounds like an interesting idea.

[Nessalco]

FWIW, I'm working on an article about making pumps of any size from carbon fiber - light, quick, and cost effective. I've gotten the text completed, and just need to take pictures of the process. Since I have to order more stock to do the pictures, it's going to be a month or so.

 

The pic below is of 2.5" & 3.5" pumps I made several years ago, and use frequently. I've 'perfected' the process since then, and need to remake the 2.5" since I use it most frequently.

 

 

KO