Best glue for vacu-formed terrain? (1 Viewer)

[Bid_kahuna]

I got my ancient Jean Hoefler Grand Canyon diorama base out of the garage today. I think I got it for my 5th birthday back in 1970 or so. It's in pretty good shape, but there are a few large splits in the plastic at the corner mountains and I want to repair it. It is made out of that thin white vacuformed plastic that they use for war game terrain and relief maps, painted on the outside. It's also 45 years old. What would be the best kind of glue? Something that will hold yet will not eat the plastic. Would a simple hot glue gun on the inside of the crack be OK? Or would the heat of the glue be too much for the plastic and melt it? Any suggestions would be highly appreciated!

 

[theBaron]

It's likely made of styrene, so glues made for styrene would be best. I use Testor's tube glue, and also Plastruct's Bondene liquid glue. Tamiya also makes a liquid glue for use with styrene.

They work by softening the plastic, welding it, in effect.

However, you might want to provide some backing for the weak spots, especially where the cracks are in areas of sharp relief, like the top of a ridge, say, or where the relief forms an acute angle. In those cases, I would take some 2-part epoxy putty, like Aves A&B, and use it to fill in the weak areas from behind, and to provide additional strength against future stresses.

For cracks along (relatively) flat stretches, you might want to buy a sheet of Evergreen or Plastruct styrene sheet and make some patches to put along the crack, on the underside, and flow some liquid styrene glue into the join. That will also provide some additional strength.

If it's not styrene, I would use CA glue or 2-part epoxy glues, but I would still try to strengthen the cracked areas from the inside. I would still use putty in the relief areas, and instead of styrene sheet, I could see even using pieces of cloth, to back up the cracks, in the flat areas.

Hope that helps, prosit!
Brad

 

[Wolfgang_UK]

Hi,
45 year old styrene can behave very tricky trying to repair. As a plastic these materials are never really "finished" meaning that they keep on changing their physics over the years. Resulting in becoming brittle and do easily crack.
A friend of mine had the same issue with a styrene vacuum formed railway scenery piece by Märklin dating back to the sixties. Epoxy clay did not work since the cracks where to long and the added pieces jumped off once the piece was touched or flexed.
Styrene Glue or any other chemicals where also dismissed so he used newspaper stripes and a lot of high quality wood glue instead. He cut rather long 3 cm wide strips out of a newspaper put it into warm water for about one hour and applied the
generous amount of wood glue to each individual piece covering the inside of the part in a criss cross pattern. It did not shrink crack or got loose by any means. Never done it myself but you might want to give it a try.
rgds
Wolfgang:salute::

 

[Bid_kahuna]

Thanks very much for the advice, guys! I think I am going to try the wood-glue and paper backing method. I'm not sure if styrene glue would be the best for the kind of cracks I am seeing on my Grand Canyon.

Thanks again!