(Liquid) acrylic suitable for scrubbers?

Mdemon

Thinking about scrubbers and what they are made from... Is a moulded scrubber any weaker than one made from extruded ABS or acrylic? Not an engineer, so would appreciate a steer...

I'm sure I've seen some acrylic scrubbers in the past but they seem to have been made from acrylic pipe. I have access to liquid (pourable) acrylic and wondering if moulding one based on an existing design would be possible... It's great stuff for potting electronics. Is fibreglass an option?

Your thoughts?

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Philippe GERIN

I made an acrylic scrubber canister for my Classic Kiss from cast acrylic pipe found on Mc Master. Here is what they told me when I asked about the ID size variance:
Manufacturers start with liquid acrylic poured in a mould and spin it to form a layer of acrylic of the desired thickness on the walls of the mould to form the pipe. Considering the mould never spins exactly round plus the material cools down differently in different spots, the tube/pipe ID is never exactly round but slightly oval (as opposed to PVC that is extruded).
Therefore I had to have both ends machined to have a good seal.
Best
Philippe

Mdemon

Thanks Philippe!

__________________
www.southwestmafia.com

"small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!"

The WRONG Attitude will get you killed.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

Scuba_Vixen

Adding to what Philippe mentioned; When the mold is spun, centrifugal force compacts the resin and forces the air bubbles out making it much stronger than if you just cast it. Vacuum casting might help some, but plan on a thicker wall if you cast it yourself.

The diameter inconsistancies are the same issues as noted with the DIY PO2 meters using polycarb/acrylic tubing. If you don't machine the ID at the ends slighly, the O-rings leak.


Darlene

Crazyduck

For work purposes we tend to use Lexan over Acrylic.
Acrylic tends to split, shatter, and is hell to drill.
Lexan (trade name) tends to resolve a lot of those issues.
McMaster Carr can sell products with either cut ends or ground ends for specific tolerances.


Depends if the material will have any impact issues or if it is used in a case?
You also need to think of thermal issues…

Andrew

apitkin

Steve Lindblom's book 'The Divelight Companion' on building dive lights is a very useful guide to working with plastics and making them watertight.

http://www.airspeedpress.com/newlitebook.html

It covers cutting, machining, gluing and finishing various types of plastics for building canister lights in a very practical 'this is how to do it' way.

Highly recommended.

Andy

Mdemon

Thanks for all your kind help guys!


I've had my eye on that book for a while - I'll stick it on my Christmas wish list!

My interest in moulding is purely down to my lack of lathe and general machining equipment (and ability!).

I'm finding it hard to find short (~1m) lengths of ABS plastic tough enough to make a scrubber from. Likewise acrylic, although I'll try McMaster C again. Even if I managed that, I'd still have more fun than required sorting the end to accept an Inspo head! Since this is just an experiment, I can't justify huge amounts of cash on either parts or machining...

Thanks SV for the info on strength - I suspected that might be the case. Since the scrubber may have to support the unit, I was planning on making it thick. I also want to use the original Inspo cartridge so thermal issues are lessened, but worth thinking about.

Should be an interesting (and probably quite messy!) winter project.

__________________
www.southwestmafia.com

"small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!"

The WRONG Attitude will get you killed.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

apitkin

RS sell ABS pipe with a 4" ID. It's class E (15 bar). You have to buy it in a 2m length, and it's not cheap, but it's bombproof. The wall is about 10mm thick. Best of all, you can glue it easily with solvent adhesive (called something like Tangit-ABS). Don't inhale whilst using it though, except for kicks...

That means that you can make something with tools from B&Q and glasspaper. You shouldn't need a lathe, although that'll make it look prettier. I made a couple of light canisters out of the stuff. For fun, I tried to break an off-cut piece of pipe with both a large axe and a sledgehammer. Failed miserably.

Andy

Crazyduck

Visit Duncans site
www.sump4.com

He shows a great item- rocket tube (used). Cheap and bomb proof- hehehe.
I might have a hard time getting the shell threw customs through .

He also shows a gas pipe material.

Also visit a few home builder sites like Wern, and Tom Rose (HB Master.)

Cutting seems not so hard as making all the dang bits work together.

Have fun- Andrew