Reddit reviews IPS Weld-On 3 Acrylic Plastic Cement with Weld-On Applicator Bottle with Needle, 4 oz Can, Clear

As other people said, spraying on a coat or fifteen might work.


But I think the best option (at least in terms of quality) is gonna be to make a mold one way or another. That's pretty difficult to do with paper, since it's
A: Not totally sealed, so the mold material can get inside and completely ruin the mold.
2: It's not waterproof so it can get just ruined by the liquid in your mold material of choice.
III: Some molds get extremely hot when they're curing, which can damage the mold. And
four: paper doesn't hold up well under weight so you'd be hard pressed to make a two-sided mold that wasn't awful, meaning you could only have something with one totally flat side.


I think the best option would be to find some kind of spray layer that you can apply safely (or paper mache, I've heard that works pretty well at improving structural integrity) and beef up the object with that first, then make a mold of that. Another idea I've toyed with before but never tried was to reinforce the model from the inside. My plan was to go with foam crack sealant, but I haven't had a chance to try it yet.


Alternatively, get yourself some styrene sheets and make it out of those. They're really pretty excelent for model building if you have the patience and care to cut out the sections. I'd suggest cutting out all the external shapes (IE not the internal tabs or anything) from a papercraft model out of the styrene, just a bit oversized, then assembling the papercraft model.


You could then use the model as a reference for how to assemble the styrene (using this glue to seal them together. If you hold it in place for a good couple minutes or have an internal support of some kind, it'll hold its shape remarkably well.) Once it's assembled it'll be pretty damn sturdy, and you can clean up any rough edges with some sanding and fill any gaps with a bit more glue and some scrap styrene slivers. Then you have either a pretty decent hard plastic toy right there, or you can make a mold of it if you want a soft kinda toy of some kind.


Hope that helps!

Another cheap, quick solution that can look quite nice is styrene. All you need are styrene sheets, an exacto knife, a ruler, some brush-on adhesive (can be had cheaper), and a little paintbrush. Cut two pieces of styrene, hold them together, brush a little adhesive on, and there ya go. Popular with modelmakers.

It's pretty tough stuff, bonds quickly and sturdily, it's very easy to work with, and it can take filler/paint quite well if you want to get fancy.

Maybe you could use some plastic angle molding on the corners as well? Or something like this?

Edit: Actually here's some acrylic solvent, it basically welds the two pieces together.

ok, since it's pla your solvent choices are limited. Acetone might soften the pla up a bit, making it easier to remove, but since it's only going to work at best partially (it doesn't actually work on pla, only on whatever other additive plastics are present in the brand of pla you have) you really have only a few choices, and they're all nasty chemicals. Tetrahydrofuran, and Ethyl Acetate are the two I know off the top of my head. They're both moderately nasty stuff and possibly cancer causing so take care if you decide to try them. It might be easier and safer to get some of this:

https://www.amazon.com/Acrylic-Plastic-Cement-Applicator-Bottle/dp/B0149IG548/ref=sr_1_1?ie=UTF8&qid=1470760033&sr=8-1&keywords=ips+weld+on+3

from the reviews it seems that it's a pretty effective pla solvent, so letting some of that sit on the glass for a few minutes might remove the discoloration.

https://www.amazon.com/Acrylic-Plastic-Cement-Applicator-Bottle/dp/B0149IG548

That stuff? Should work great, it forces a chemical reaction that melts the edges of the material so it can rebond. Just let it sit for a day or two before using the block.

The bubbles form naturally during the bonding process; it states this on the back of the container. Here is a link to the Amazon page where I purchased the acrylic cement.

> The product you bought might call it weld, but it really, its not.

This is the same product and technique people use to build acrylic aquariums. If it's good enough for them, it's good enough for me.

> Why do you think all mods/pro today use rubber gasket.

Here's an acrylic reservoir made by Swiftech that is joined with cement and not gaskets.

Edit: just responding to your ninja-edit, I use Weld-On 3 because I feel the faster bonding time makes the pieces easier to work with, plus it's one of the most commonly recommended acrylic adhesives along with Weld-On 4.

There are solvent based glues for acrylic that would avoid some of the issues you had with hot glue (like the random strings). You typically have to clamp/hold in place the pieces until it's set, but they work really well. This is an example.

This stuff will weld it together beautifully:
https://www.amazon.com/Acrylic-Plastic-Cement-Applicator-Bottle/dp/B0149IG548/ref=sr_1_3?ie=UTF8&qid=1502135033&sr=8-3&keywords=Weld+on

If it is injection molded plastic I would suggest a solvent based glue like Weld-On 4 Cement. It is very thin like water and will get get in between the plastic parts. This type of glue works by melting the plastic together, making a very strong bond with very little contact area. Apply it with a needle applicator, you can buy it in a kit like this. https://www.amazon.com/Weld-Acrylic-Plastic-Cement-Applicator/dp/B0149IG548/

Hold the button cover on and very carefully flow the solvent from the needle into the seam between the parts. Hold or gently clip (without deforming the parts) for about 5 min the allow to cure overnight.

Good to know. I was going PETG to PETG and this stuff was the only thing I could find that worked: https://www.amazon.com/dp/B0149IG548