discussion Help needed with a sticky problem

[Guest]

Sorry for the pun but I'm experiencing a glue problem and I'm hoping someone out there can help me out. I am converting the 1/72 HMCS Snowberry to R/C and was nearing completion but have discovered recently that bits keep falling off the boat!!! I have tried different glues i.e. Poly Cement, Precision Poly Cement as well as Super glue (Precision Max) for various parts of this plastic kit but everything seems to drop/fall off when touched by human hand. The said parts are painted with matt enamel prior to gluing and all appear to be secure and safe for a few days but then the slightest touch has bits keep falling to the floor. Can someone give me any idea what I'm doing wrong? I have previosly built plastic models when I was a young boy and can't remember having this problem before. All of my model boats are made from wood or with GRP hulls and I've had no problems.

 

[Guest]

The said parts are painted with matt enamel prior to gluing

I think that is the answer to your question. In effect, you are gluing paint to paint so the joint is only as strong as the paint to the plastic. You need to have bare plastic on both surfaces of the joint.

 

[stona]

Yep,it sounds like that to me too.

Steve

 

[Guest]

Thanks guys, I was hoping that I'd get a different answer to that - I'll have to scrape away the paint and re-glue everything - but thanks for the advice it is really appreciated

 

[Guest]

As the guys rightly say the paint seals the plastic so the cement cannot get to it to disolve the surface of the parts and so they cannot fuse together. You end up with a blob of cement insulated from the parts by the paint, which isn't affected by the cement.

The remedy isn't as bad as some of the paint disasters we might encounter!!

if you are having problems with cyanoacrylate glues though, superglue, then you might have some release agent still on the plastic so you might have to wash the parts with soapy water or maybe carefully wipe with a cloth dampened with thiners.

A lot of other glues such as PVA type glues simply won't work on polystyrene.