Acrylics: EMA Plastic Weld / solvent cement, Methylene Chloride only? & related questions.

[Toria]

There has to be a more economical way to get supply than £3.50/57mls. I'm going through plastic weld at an alarming rate while making acrylic things. 

On the back it states "Dichloromethane (Methylene chloride)" as far as i understand this is the main ingredient, but the internet doesn't seem to confirm/deny this, and i can't ocate a COSHH sheet for it, anyone know?

EMA model supplies is located in SE27 0DN, they sell 500ml for £7.20, tempted to pick one up (delivery £8 *sigh*), unless some nice person happens to live down that way? :D

Or, i ~could~ purchase 1L of Methylene chloride on ebay for £10 (including shipping) but i'm a bit reluctant to do that without first confirming the composition of plastic weld.

Syringe application - how does it not melt the plastic syringe?

Does it only melt and bond plastic as it evaporates?
If so, in June i hopefully will be able to get hold of lots of various sized syringes, and will be happy to share.

Or would you recommend switching to a different method for sticking my acrylics together?

[Adrian Godwin]

I believe ether also works (is it the same thing)?

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[Brendan Sleight]

Toria,

I going to ask a most probably stupid question.  But what is wrong with pound shop super glue ?

BMS

[Toria D]

Cheap glue doesn't sufficiently bond the acrylics. I have loads of really nice jr e600 superglue that won't even bond it. As soon as it dries it just peels right off.

[Brendan Sleight]

Thanks, I've learnt something today

[Brendan Sleight]

On Wednesday, 29 April 2015 18:48:20 UTC+1, Toria wrote:

On the back it states "Dichloromethane (Methylene chloride)" as far as i understand this is the main ingredient, but the internet doesn't seem to confirm/deny this, and i can't ocate a COSHH sheet for it, anyone know?

Maybe - http://www.wikidoc.org/index.php/Dichloromethane
"Dichloromethane (DCM) or methylene chloride ... Often sold under the brand name of "EMA Plastic Weld" it is also used extensively in the modelmaking industry for joining plastic components together"
Link also details toxicity.

[Simon Howes]

4D model shop sell it in biiiiiiig tins.
Acetone also works equally well. I use both of these for solvent smoothing 3D prints, the plastic weld is more aggressive, while the acetone is gentler, but tends to blur small details.

They also sell a mini plastic squeeze bottle applicator with a hyperdermic needle. The needle's plastic is acetate I believe (unaffected by solvents) which is why it and syringes don't melt. I think the bottle is polypropylene. Some plastics just aren't affected by solvents like others are.

Just don't make the mistake of putting the bottle down on a table and making excited hand gestures, as I did, to come away with needle with a squeezebottle of horrible solvents stuck in your hand (removed so very, very carefully making sure to grasp bottle by the collar and not squeeze it!)

On 29 Apr 2015 18:48, "Toria" <tor...@gmail.com> wrote:

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[Des Quilty]

Perhaps you might want to consider a metal ear syringe..

 

I haven't tried it but can't see why it wouldn't hold up, perhaps there may be some rubber seals in there which might not like the solvent..

 

http://www.ebay.co.uk/itm/Ear-Wax-Removal-Syringe-4-OZ-Chrome-finish-/151645646449?pt=LH_DefaultDomain_3&hash=item234ec8ee71

 

There are some second hand ones for sale on ebay which may be even cheaper.

 

I use pipe weld quite frequently to fix the ABS panels on my motorcycles...it doesn't last forever so you may find if you buy a big batch and don't use it fast enough it may loose its potency..

 

I have also found some plastics used in a seat pan which look like ABS but don't melt with pipe weld...

[Toria D]

AH! Hadn't realised 4D stock the big tins, £10.20 is a fair price for it too. (I will refill my small EMA plastic weld bottle from it and make a stand for said bottle so i don't knock it everywhere this time.... x_x  )
I'll pop there tonight and get a nice big tin. <3

I've tried acetone before but find the bond isn't strong enough.

At some point i'll test it in the syringes i have, see if the darn thing melts or not.
Ear syringe is unfortunately too bulky and un-precise for my tiny drippy needs.

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[Simon Howes]

Grab one of the mini squeezi-bottles with the derp-needle - they sell them too!

The needle is really fine so it only let's out a few drops, its perfect for applying minute amounts of solvent to get into the seams, without running over the plastic and ruining your finish. So long as you don't accidentally stick yourself with it, I can highly recommend this application technique :)

[Eugene Nadyrshin]

The most convenient way of dispensing plastic weld is using a pumping dispensing bottle like this one on ebay. Also it doesn't spill if you knock it over :)