Introduction: DIY Vacuum Room for Small Resin Castings

About: Maker from France. Curious about everything

Have you ever needed a small vacuum room for resin casting because your clear resin casts were full of bubbles?

Well i recently had that problem so i figured out a solution, i hope you'll enjoy it

Step 1: What You Will Need

I do not need a big resin cast so i took a 1kg candy box and made sure it was airtight.

You will need a syringe or a hand pump

My syringe was 60ml and it was a perfect fit for my leftover nylon tubing from my aquarium.

You will also need a three way cross for your tubing and two one side valve (also left over from my aquarium but they're cheaper than you'd expect)

Step 2: Building It!

So now that you have all the requirement make a hole in your box the size of your valve and put the input side of the valve on the inside, then seal it with glue (this ensure that air only leave the box through the valve)

DO NOT put any glue inside the valve! so be careful!

Now you can connect the pump to the tube, and the tube to the three way cross to two smaller tubes, one leading to the valve on the box and the other leading to the other valve, to make sure that air only leave through it

(english isn't my nate language so i can't really explain this correclty, but i made a drawing that will hopefully make you understand how it works!

Step 3: The Pros/cons and Why Yours Might Not Work

So here is what i got from using it a few times:


Really cheap

Fast to make



The pump is hand powered

Plastic box may bend if you apply too much pressure

(a little bit of bending is ok but too much may ruin your airtight box)

No safe way to deppressurize it, so be careful

"Help, mine isn't working"

A few reasons can cause that to fail:

Your pump isn't airtight aswell for some reason

fix: use cable ties where the cable change, or use electrical tape if you screw around (not sorry for the pun)

Your box isn't airtight

how to be sure: the marshmallow test! put one or two inside your box and start pumping! you can have different results:

The marshmallow was inflating, and suddenly looks like an old person: you have a good pressure no problem

The marshmallow is pulsating like a heart: your pump works well, but there's a hole in the box

The marshmallow is not caring at all: either there's a big hole somewhere, or your pump doesn't work

fix:glue or silicone caulk, and if your box is totally ded, change the box

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