Some resin advice?

[Munty Scruntfundle]

Hi folks. This might not quite belong in this section, but I've assumed the wood working guys have more experience with resin than the metal blokes. I'm both!

I need to make some cylinders of resin with loads of sparkly bits mixed in, emulsified if you will. I have no idea what the mass of these mixed sparkles are but I very much doubt I'm going to match resin so everything floats.

So, I thought, could I keep the resin moving while it sets. I haven't been able to find any subjects on this, so maybe it's just not a good idea. I was thinking of brimming a cylinder and putting it in a rotational rock tumbler.

Has anyone tried this? Is it a viable solution or just a stupid idea?!

Many thanks.

 

[baldkev]

Firstly, mix a small test batch a put it in a shot glass with your favourite sprinkles, mix them and observe. You'll probably find the sprinkles are suspended successfully and dont sink, therefore requiring no further action.
'If' you need to move them around, beware of the timescales. Polyester goes off faster and i successfully created a wave / rippled effect on a table i did, but epoxy wont do quite the same as it sets much slower and wants to level itself more.

Lastly, be careful. The general rule of thumb is a pour of resin needs to have surface area for the reaction to dissipate, so a lunchbox of resin is fine. A tumbler if resin is more likely to get hot. In extreme cases, it can catch fire. It can also crack as it heats and sets and then cools.

I once had a roofer who got his ratios wrong with a mix ( and it was in a big bucket ) and the resin smoked and shouldered for a while!!! A lot of wasted material.

Mix it and let it set outside

 

[alex robinson]

Sinking or not will depend a lot on density. Metal powder definitely sinks, some plastic would float.

Casting resin has a maximum safe thickness. Epoxy tends to have a greater safe depth and is much clearer as well as being nicer to work with. The most I have seen is 100mm per pour, but it will take a week to set! You can call the smallest dimension the thickness however, so a column 100mm wide could be as tall as you liked however.

Heat build up will depend on 3 things.

The higher the outside temperature, the faster the reaction, so the more it will heat up.

Heat dissipation can also vary. Some resins have different pour depths depending on how conductive the mould is. Metal would allow a greater depth than polystyrene. People who make big resin tables often use fans to keep it cool while setting.

The volume of the pour also has an effect. The bigger the volume, the more the risk of runaway heating.

I cannot see why keeping it moving wouldn't work and would be interested to see the results!

 

[baldkev]

I cannot see why keeping it moving wouldn't work and would be interested to see the results!

Some good points above.... for casting a tumbler, epoxy is the best option, less shrinkage, better impact resistance and lots of other factors, but it takes a while to set up, so it'll need regular stirring if the particles start to settle. You'd want to mix up first thing and be around all day just in case.

Once it starts happening, and going off, you often get a gloopy effect, where it gels up, so i strongly supsect the mixing might cause the sparkles to become less evenly diplaced and get stuck to the more gelled bits ( if that makes sense )

 

[sawtooth-9]

Need to know the size of the cylinders you want.
There is a very clear embedding resin ( from marine shops ) which is an epoxy, and does not create too much heat. If interested, I will send through the details.
What are you going to use as a mould ?
I think stirring to keep the sparkles in suspension, may not work - but a slow rotation of the mould may work quite well.