Acrylic welding with Methylene Chloride
 

I went to Industrial Plastics and Paints today to pick up the supplies for my aquascaping. 1/2" acrylic rod and some off-cuts of acrylic sheet. Also picked up some Methylene Chloride and a nifty little applicator for welding. The guy asked me what I was using it for and I told him about my build. He said Methylene Chloride was not reef safe and after time could leech into the tank and cause serious harm... so I'm a little confused.

Isn't that the standard welding cement everyone uses for acrylic sump builds?

Should I or shouldn't I use Methylene Chloride for welding acrylic?

Never welded acrylic before so I'm a little stumped.

Thanks for the input.

Most people I know use a brand of acrylic "glue" that is called Weld on.
This also contains methylene chloride. So I don't see a problem, but hopefully other people that have used it will chime in.
But use the cement in a well ventilated place and wear thin latex gloves.
Methylene chloride is a known cancer causing agent.
Don't breathe the fumes nor get it on your skin.

Methylene chloride is used to weld the acrylic but you must have very tight joints. The MEC melts the acrylic so it fuses together. When it evaporates off, the acrylic is left in one piece. I would rinse the acrylic after it has cured(for 24hrs) and you should be fine. I made my own 4' x 8' tanks with that method. Been using them now for 11 yrs.

I believe the product is Weld On #4 and it's mainly MEC.

Just google MEC and Weld On #4

The guy at IPP in Kelowna never mentioned an issue when I bought it for my sump. been up and running for six months with no problems.

Yes, if you dumped Methlylene Chloride directly into your tank their MAY be a problem When using to glue acrylic once it evaporated nothing is left. It simply melts the acrylic allowing a extremely strong joint. Methylene Chloride isn't the safest substance and you should not inhale it or allow it to get on your skin. Long term exposure has been linked to bladder cancer.

Ya, as long as you don't use it underwater, you're fine. Not sure that there is anything you could use in it's place. I've built skimmers and reactors for years with it, and acrylic tanks are built with it. I'm guessing guy at shop has been sniffing it :)

Or covering his company's butt in case something happens, he can claim that he told you before that it was NOT "reef-safe". I've used weld-on and never had a contamination issue.

Thanks for the info guys, it's put me at ease. Brad is right, he's probably covering his butt and doing a little sniffing on the side.

No, I just said the sniffing part :) I imagine he's a new reefer that read something on the internet. Covering butts requires documentation, not a sales clerk mentioning something.

My bad. Perhaps I should put the lid back on the bottle. Here's their documentation: http://goindustrial.ca/index.php/en/...ne-chloride-mc

Probably just don't leave it open all day, and don't drink it. For gluing a couple things together, it's not going to kill you. Gasoline probably has a very similar data sheet, but we stand over it pumping it into our cars without worrying about it :)

Should have told me earlier... I mixed some in my egg-nog last night. BTW, I love the smell of gas. I still have a collection of gas scratch and sniff stickers from the 80's.

Oh, sorry, no, you're ok. I read that eggnog neutralizes all the bad parts.