'Hardening' a Cast Item

[HerbDiehr]

A fellow wants me to make some small units (3 inches by 4 inches by 1/2 inch) to hold a set of wires and some tiny LED lights, for a robotics part. The current unit he's using is pretty solid and can bear heat from the LED's to 70 degrees C.

Will resin take 70 C?

Can resin be screwed into another unit (will the resin hold up to the screws? Not a weight-bearing issue, just for stabilizing the device with LED's)?

If it cannot take screws, can it be 'hardened', somehow?

If it cannot take the heat, can it be 'hardened', somehow?

This pays very well (making part of the 'eyes' for helping blind people 'see', electronically. Could be lots of parts! Weight is a big issue and the whole unit is $500 k... (much better than my initial ideas!)

Anyone know about such things? Info would be VERY appreciated...!!


Thanks!

Herb Diehr
Willis, Michigan USA

[mangozac]

It's hard to reply with this limited information. I assume the part will be clear? Most polyurethanes will get a bit flexible at 70°C. You can get high temperature polyurethanes though.

The other important thing to consider is the exothermic temperature of the resin as it cures. You want to make sure it's not high enough to damage any of the components. It will need to be a fairly slow curing product.

You can screw into resin just fine. I'd recommend pre-drilling and then using self tapping screws. You can tap resin so that it will accept a standard machine screw, but below around 5mm the thread pitch becomes a bit too fine and the resin will strip easily.

[Fleafa]

There are so many different resin formulas out there, it is a case of researching them and checking out the materials documents for them. Heat tolerance is often listed and there are resins out there designed to take higher temperatures.