How to Bond Sintra

[Cinobite]

Hello!

I didn't see a "building" section of the forums so I hope it's ok to ask here.

I LOVE sintra and have been using it for a Colonial Marines armour piece (my first cosplay). I'd like to use it again but need it thicker.

Here's the thing. I've been using 3mm 6ft panels of sintra for work for the last 6 years! So I have loads in the garage. Any ideas on how to bond 2 sheets together (as smaller pieces) to thicken it up to 6mm? For the Aliens armour I used super glue which is amazing as it melts the sintra together, but that just gets REALLY expensive! Is there some kind of paste or alternative I can buy to coat the sheets and stick them together before heat shaping?

TIA

Here's my (unfinished) Aliens armour if you're interested;

 

[Pro Mod]

You can buy solvent which will weld it together; alternatively you could use PVC pipe cement which is more of a gel. These products are generally available from plastic stockists or try a local sign maker.

One bonded together it may be a bit harder to form as you've now got three solid faces compared to the original two.
Also probably best to leave it overnight for the adhesive to fully cure before heating it up.

I'm curious about superglue welding it together - that’s something I've never seen.
Armour looks great!

 

[joberg]

While PVC pipe cement works wonder on Sintra (and other plastics) you should test a small piece and see how it's reacting to heat (I don't know if you vacu-form your armor...great one, btw) and how the layers are holding together over time: sometimes the heat has a tendency to make cracks appear in you formed plastic. Good luck.

 

[yaris]

The problem will be getting an even coat of any adhesive over a larger area...you say 6' x ???....that's a large area that will require an even complete coat...maybe thin meth chloride with a disposable roller, but you'd have to work fast, thicker MC would be better, but then you get into the unevenness potential.

Probably easier to get 6mm sheets....or cut the sheets into more manageable sizes

 

[Cinobite]

Thanks for all of the replies.
What I'll do is cut the pieces to shape first in 3mm and then double them up. That's what I did with the Aliens armour.
It is harder to shape but still works, just needs some extra sanding attention to remove the "holing" / rough effect that you can get.

I could use 3mm, but I feel it would look a bit "tin foily" and weak.

The reason I want to use double 3mm is that I have loads in the garage from work that usually gets thrown out (until I realised I could use it for cosplay!) So didn't want to spend money on new 6mm sheets

 

[Pro Mod]

Methylene Chloride won't bond Sintra (well it doesn’t in the UK) you need a different unpleasant / aggressive / dangerous solvent called Tetrahydrofuran.
I would't recommend using a paint roller and any solvent - too many droplets flying through the air.

 

[Cinobite]

Thank you. Any brand names to look out for? All I keep seeing is generic superglue and PVA

Also, if I may, any tips on cutting sintra to shape? I use a craft knife which is near perfect, just so time consuming. I have tried a dremel with a disc but even at the lowest speed it's too fast and burns the sintra

TIA