Mold making

[Phil K]

I'm going to try and make my own resin casting molds. If you have tried this, what type of silicone do you use? Alumilite has some good stuff, but it comes in expensive large volumes and my pen making budget is already under tight scrutiny (but that is another thread lol)

 

[1080Wayne]

For pen blanks ? Single use (disposable) , or re-useable ? Round or square ?

 

[Curly]

Smooth-On is what I used to make Marla's moulds. She cast polyester resin (PR) so we used the Tin cure, it is pink. For epoxy you use Platinum cure which is blue. PR didn't need a mould release but I used one with the few epoxy we tried. I never used Alumilite so don't know which you would use. Go to the Smooth-On website and see what it should be.

 

[egnald]

I used 3/4-inch, Schedule 80 PVC Pipe and do vertical pours. - Dave

 

[NJturner]

I got put off by the price of the silicone mold making stuff, so instead did two things - I first bought white cutting boards and cut them up into rectangular molds to start, screwing them together tightly with Kreg screws and cut to size to make 4 blanks per. Cost me less than $10 for two molds. I've since switched to vertical pouring and like @egnald said use schedule 80 PVC pipe with some plugs in one end of each tube. You can buy the plugs and a nice pressure pot rack from SpeakEasy Emporium to make things easier. I did break down and bought a gang silicon vertical mold from PTownSubbie as well and found it to be really good, so haven't looked to make my own silicone ones again.

 

[JohnU]

Besides all of the recycled materials out there you can use as molds (just not #6 code), Another option, if your casting blocks and not round blanks, just construct your mold out of smooth cheap pine and wood screws. Then cover the interior surface with either "Tuck tape" (brand) or a thick packing tape. I usually cover the wood surfaces and then screw it together so the tape also acts as a gasket between joints. Works great but you may need to replace the tape after a few pours because the resin heat will eventually distort the tape. I use this method for all of my larger or odd shape casts because you can make it any size or shape you need. If I use epoxy I also tape the outside seams with masking tape, just in case an inner seam leaks during the longer curing time.

 

[egnald]

Besides all of the recycled materials out there you can use as molds (just not #6 code), Another option, if your casting blocks and not round blanks, just construct your mold out of smooth cheap pine and wood screws. Then cover the interior surface with either "Tuck tape" (brand) or a thick packing tape. I usually cover the wood surfaces and then screw it together so the tape also acts as a gasket between joints. Works great but you may need to replace the tape after a few pours because the resin heat will eventually distort the tape. I use this method for all of my larger or odd shape casts because you can make it any size or shape you need. If I use epoxy I also tape the outside seams with masking tape, just in case an inner seam leaks during the longer curing time.

John, that's an outstanding tip! Thank you!!!

 

[Woodchipper]

Good idea. Have seen some on YouTube using PVC pipe.