Best/ideal product for bonding plastic (keyboard cut down)

[Aran.E99]

Hi guys,

I'm currently doing a G80 cut down however I don't know what to use to bond the plastic. I don't really want to invest in plastic cement/adhesive or similar products because they're fairly expensive and I will never use them again. Would epoxy (the 2 part stuff from a hardware store) work well for this or should I just get some proper plastic glue? Since I'll be taking it to University with me, its gotta be pretty strong.

Cheers

[Tactile]

If the plastic is ABS you can use acetone as a cement, and it works very well. Here in the US it's available as nail polish remover, thus very inexpensive.

[Aran.E99]

you know what - that might work perfectly. My cuts aren't perfect but I could melt some of the scrap plastic in acetone and use it to fill in the big gaps. Thanks!

[fohat.digs]

JB Weld is the best epoxy (original slow cure) and it might be worth spreading a reinforcing layer on the back side if you have clearance.

[Findecanor]

ABS scraps in a air tight jar, cover with acetone, leave overnight.
I use empty KOO marmelade tins with a plastic lid. I have seen these plastic lids on cat food tins also.

Work fast. Thin layers or it will never cure and/or you risk warping. DON'T SPILL on plastics or on your clothes.

Poly cement isn't that expensive otherwise. Get it where plastic model kits are sold. Revell in blue bottle or Humbrol in yellow bottle with long pipe. Should cost 4 GBP or so.
That's about as much as you would spend on acetone. There might be smaller tubes of plastic adhesive for less.
I tend to use both adhesive and ABS goo for different things.

[Aran.E99]

Thanks guys, I think I will use the aforementioned acetone-abs glue then fill the big gaps in with epoxy. I might do a follow up on this if it works!

[Leslieann]

ABS scraps in a air tight jar, cover with acetone, leave overnight.

This.
It's what we do with 3d printed parts and works perfect for ABS.  Beware, the acetone can alter the surface finish.

If it's not ABS (uncommon), an epoxy or JB Weld will be best.

[OldIsNew]

I haven't used it but it does sound like the ABS/acetone would give the cleanest results for a seam. For general plastic bonding, I've have very good results with Loctite Epoxy Plastic Bonder. I don't know if it's available where you are but it only costs me about 4 USD in my local store.



Of course it doesn't work with polyethylene/polypropylene - and since we're on the topic of bonding plastics - does anyone know of a bonder, other than heat welding, that does work on those plastics?

[Findecanor]

Of course it doesn't work with polyethylene/polypropylene - and since we're on the topic of bonding plastics - does anyone know of a bonder, other than heat welding, that does work on those plastics?

There isn't one in practice. PP and PE are impossible.
When I checked some years ago, only 3M had some industrial adhesive that was not available to consumers.

Stickers do stick to those plastics though... but sticker glue stays sticky forever. Maybe you could use stickers or vinyl that you could glue onto, but do make a test beforehand. Plastic sticky tape does not work because it is made of PE.
I have heard that stickers stick better to PE if you first flash the plastic with a flame: apparently it changes the surface tension.

[Aran.E99]

Thanks so much guys. One final question - If I use nail polish remover, what % should be acetone? I assume I should avoid any watered down/added chemicals but how would this affect the bond? I assume it would cause curing/hardening issues?

[Findecanor]

Thanks so much guys. One final question - If I use nail polish remover, what % should be acetone? I assume I should avoid any watered down/added chemicals but how would this affect the bond? I assume it would cause curing/hardening issues?

It should contain acetone and/or some kind of acetate/etanoate ... and 0% anything else.

But do get your acetone from the hardware store! You'll know it will be pure acetone. A large bottle should cost you 5 pounds, has many uses and will last a long time as long as the top is securely on.
BTW. Plastic model glue is often butyl acetate and some thickener.

[Aran.E99]

cheers!!!

[fohat.digs]

But do get your acetone from the hardware store!

And if you have a fingernail polish-using other, you can get the same product for at least an order of magnitude less money.

[DiodeHead]

MEK and dichloromethane I've heard a lot but never tried, I think both of them could be found in the hardware store as paint solvents or strippers.

[Findecanor]

And if you have a fingernail polish-using other, you can get the same product for at least an order of magnitude less money.

Your SO won't be happy when she notices that her bottle that was full yesterday is now half-empty ...

MEK and dichloromethane I've heard a lot but never tried, I think both of them could be found in the hardware store as paint solvents or strippers.

There are health risks with those and they are not available over the counter over here. They are sometimes components in adhesives for plastic, especially for bonding PVC.
You also often want your adhesive to not be too runny or smell to high hell: so, ABS goo or epoxy it is.