Retired - No Title

Sorry, no idea what you are on about! Maybe a web link could give us an idea!

I'd use non-threaded rod bonded into a blind hole in the block. Threads are a natural weakness, especially in plastics.

Thanks. I actually forgot what the original Forum Thread was. I tried to get a separate picture of just a rectangular mold and the bandaged rod & plate but no luck. I will try to send another picture:

Hi,

I have seen posts on this topic for months (years?). This is the first time that a picture has come through. Your molds won't work with sand, as the drag effect from attempting to push the plate out will deform wet sand/collapse dry sand. You simply need to make your molds with detachable sides, form your piece, and place it against your existing structure.

Similar molds are manufactured to cast plaster castle components, they are made from soft rubber to bend away from your finished piece and allow release without breakage. Yours will need to be harder since your material of choice never sets, while still allowing release. try a stiff rubber shell, made of three pieces for the sides and top, with a light texture inside to help the release. Make each mold in three parts that interlock but can be removed one by one when placing the finished part.

Hope this helps, pictures could have solved this a long time ago.

-Mike Lynch

Looking thru my binder on sand castles I do find a patent which reminds me of what you are saying. The page is called Patent Storm and has information about a molding chamber for green sand molds - US Patent 6463993.

I am not sure about green sand molds. On another page is one called Familytime. They mention using Nesquik container molds and the use of wet sand.

My trip to the beach with the sand molds that I had worked for awhile with wet sand as I remember.

Well, anyway.

After several recurrent threads on this topic, no solution has been reached, so maybe it isn't really practical, after all.

Quite the PUN master you are.

Which size is the plastic rod? Which size are the threads?

the sand will have to have a high degree of water content to be extrudable - or it will jam in the system and the plastic will not be able to exert enough force. This is much like earth in the barrel making a gun explode In addition sand in such a threaded mechanism will soon bring things to a halt.

You can buy internally threaded brass inserts that expand and grip into a plastic hole. Screwing in a plastic rod is then not a problem.

Google "brass inserts for plastic"

Thank you.