What is the strongest possible glue for styrene-styrene bonding?

Tenax or Plast i Weld will actually melt and fuse the plastic together making a solid bond. It sets up within one our and is fully cured overnight.

Just a thought, but if you are having trouble finding a glue that will work, is it possible to use a mechanical fastener like a screw or nut/bolt combo? Is the seam in a hidden area and could a fastener be hidden as well?

Don Stauffer

I keep an old bottle (and brush) from a commercial solvent glue, and pour the MEK into bottle when I need a refill.  The big can stays closed except when filling the little bottle.

 

 

Don, that's exactly what I do.  The bottle is open for only a very brief time while using the MEK. 

Gary

It was hard for a time to get MEK in hardware stores- all I could find were cans of "MEK substitute."  However, I am now seeing regular MEK on shelves again. I keep an old bottle (and brush) from a commercial solvent glue, and pour the MEK into bottle when I need a refill.  The big can stays closed except when filling the little bottle.

 

I don't know what the active ingredient is, but I use Testor's "Cement for Plastic Models" (3501x), which is intended for use with polystyrene and ABS plastics.  I also use Plastruct's Bondene and Weldene, on styrene-to-styrene bonds.  The both set within your required times.  As far as holding a join is concerned, I haven't had any joins break, and the welds seem to be pretty consistent.  But you also note that your joins need to resist "strong springs".  I don't subject my models to any kind of regular, planned shocks (I have dropped things, on occasion), so I can't say how well the joins might hold up to the stress.

Wait, "MEK" as in Methyl Ethyl Ketone? Wow, be careful with that stuff. That isn't what's in Tamiya Extra Thin and Mr. Super Thin, is it?

Nathan T

Definately a solvent type glue, such as Tamiya thin or Tenax or MEK. Just let it dry 2 days or so. Make sure you use a good amount of pressure while the glue joint sets up, using clamps or whatever you have.

 

I agree. I would not use MEK. It's fumes are nasty, canrcinogenic, and the stuff is pretty flamable. While that is also true of the other solvents, there's a big difference between a 1.5 oz. bottle and a 32 oz. can on the bench.

TomcatGuy

Solvent. Use staight MEK. Just give it time to fully cure. Solvent creates a chemical bond. Something none of the other glues do. It's the absolute strongest, but it will take a few days to fully harden.

Thanks - this sounds promising. Btw, can you recommend a cheap retailer and fast here in the UK? 

Cheers

 

 

Nathan T

Definately a solvent type glue, such as Tamiya thin or Tenax or MEK. Just let it dry 2 days or so. Make sure you use a good amount of pressure while the glue joint sets up, using clamps or whatever you have.

Thanks. I don't know if there is much difference between cements but I have been using EMA Plastic Weld (and have recently bought though have not properly experimented with Mr Cement S and Tamiya Extra Thin too).


I am finding that even when I use quite a lot of solvent the bond I get is never quite as strong as the original styrene (plasticard/HIPS). You may have a slight point that I have not been allowing my bonds to dry out for quite long enough. Hmm... but time is money and I cant really afford to wait 2 full days. 

I am slightly hazy as to what solvents these cements actually contain - is it Methyl Ethyl Ketone (MEK) or Methylene Chloride (or are they proprietary blends)?

For a really strong blond would there ever be a case for using acetone?

I am now thinking about using a different plastic too (e.g. ABS?) because I need to create a stronger housing for then stiff torsion spring that I am using in my model (of a novel product) and I am slightly constrained on space.

I'm not completely sure where to go next in terms of a stronger plastic AND a stronger glue!

Don Stauffer

I used to use epoxy if I needed a really strong bond, but lately I find the epoxy not sticking to the styrene.  I still find CA works best.  For a real close fitting seam, regular thin CA is fine, if the fit is not the best, then Gel CA works great, and better than the regular thin stuff.

I don't know if the mfgs are using a new formula for styrene or not, or if the epoxies are changing, but sure have had bad luck with epoxy/styrene in last couple of years.

 

Interesting - I recently bought some Plastic Fusion epoxy (I think - 2 part anyhow!) glue made by Super Glue corp, off a merchand on eBay. http://www.ebay.co.uk/itm/261508621516

I have tried 3 times now and each time it is not setting properly. It's not going as yellow as I've seen it go in videos. On the last attempt attempt I measured v carefully and mixed for a full minute and 24 hours later I could scrape it off with a fingernail. 

So I am now thinking that the epoxy itself has gone off for some reason. Confusingly there is no sell-by date on the packaging, and having never used it before I have not way of knowing if this is the case.

I wonder if your epoxy has gone off too?  :^/

 

 

 

Solvent. Use staight MEK. Just give it time to fully cure. Solvent creates a chemical bond. Something none of the other glues do. It's the absolute strongest, but it will take a few days to fully harden.

Definately a solvent type glue, such as Tamiya thin or Tenax or MEK. Just let it dry 2 days or so. Make sure you use a good amount of pressure while the glue joint sets up, using clamps or whatever you have.

I used to use epoxy if I needed a really strong bond, but lately I find the epoxy not sticking to the styrene.  I still find CA works best.  For a real close fitting seam, regular thin CA is fine, if the fit is not the best, then Gel CA works great, and better than the regular thin stuff.

I don't know if the mfgs are using a new formula for styrene or not, or if the epoxies are changing, but sure have had bad luck with epoxy/styrene in last couple of years.