mike morley Posted December 9, 2017 Share Posted December 9, 2017 (edited) I'm giving a Hornby body the RT Models treatment but am having considerable problems finding an adhesive that is compatible with whatever plastic the body is moulded from. I've tried several varieties of superglue, ranging from cheapo supermarket own-brand through to expensive Loctite and all were a dismal failure. Instead I turned to epoxy and have used both rapid and long-cure, genuine Araldite and alternative brands, and although they were certainly better, I wouldn't describe the results as good. Best of the bunch was probably Wilko own-brand rapid but even there I have found that, for instance, any that squeezes out from under whatever it has been used to attach can be pinged off when it's set with worryingly little effort and frequently takes whatever it was supposed to be attaching with it. The spectacle frames have been particularly prone to this - probably because of their small contact area - and their backs have now been scraped clean for another attempt so many times they are beginning to get distorted. I'm sure others must have met this problem and would be extremely interested to hear how they overcame it. PS. Avoid Evo-Stik epoxy! I found I needed to mix far, far more than a modeller is ever likely to use or the chemical reaction that makes it go off simply didnt happen! Edited January 20, 2018 by mike morley Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted December 9, 2017 RMweb Gold Share Posted December 9, 2017 I'm having the same issue with a Bachmann Junior loco! Nothing will stick to it or even dry! Link to post Share on other sites More sharing options...
mike morley Posted January 20, 2018 Author Share Posted January 20, 2018 (edited) I never did overcome the body's reluctance to accept glue and eventually had to resort to the least-worst option in order to finish the build (Wilko own-brand rapid for epoxy and Loctite Precision for superglue) Yesterday evening I began the next stage and promptly discovered that the same plastic dislikes something in Wilko's own-brand grey primer even more! The moment I finished spraying I realised there was too much on the front of the body and that it was pooling on the bottom of the smokebox door and the front of the smokebox saddle beneath it. I blotted the excess immediately using kitchen towel and even though it was blotted so quickly two firm dabs were all that was needed to remove all the excess paint, something in it (the thinners more likely than the propellant, I'd guess) had been in contact long enough to soften the plastic enough to leave both dab-marks and the texture of the kitchen towel embossed in it. I'm lucky in that the damage has occured in an area where a bit of typically-industrial weathering, with heavily-textured rust prominent, will hide a multitude of sins. Anyone falling victim to the same problem in other areas might not be so lucky. We've all read the warning to 'try this product on an unobtrusive area first' but I doubt if I'm any different to most in only heeding that advice with more extreme products. It wouldnt even have crossed my mind to try it with something as inoccuous as an all-purpose primer! In future, however . . . Edited January 20, 2018 by mike morley Link to post Share on other sites More sharing options...
gpplumy Posted January 21, 2018 Share Posted January 21, 2018 I've been working on a Bachmann junior loco and found no issue however one thing I have done is wash it in white spirit and then water first Link to post Share on other sites More sharing options...
mike morley Posted January 21, 2018 Author Share Posted January 21, 2018 Plastics that don't like glue or paint are very much the exception rather than the rule - hence the thread. What does make me wonder is whether it is unusual to find a body that rejects glue and paint, or if they do tend to go hand-in-hand. Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 I wonder if prepping the model using dettol or something similar may have worked? Perhaps it was a contaminant on the surface? Link to post Share on other sites More sharing options...
mike morley Posted January 21, 2018 Author Share Posted January 21, 2018 Corbs - You mentioned having a Bachmann Junior that also didn't like glue. Would you be willing to risk a quick squirt of primer somewhere unobtrusive (underside of the footplate?) to see how it reacts? That gpplumy's Bachmann Junior was adhesive happy is, I suspect, more likely to be because it came from a different batch to yours and was moulded from a slightly different blend of plastic. The manufacturers obviously do use different brews for different batches or everyone who's ever tried working on a Hornby Austerity would have experienced exactly the same problem I have. Link to post Share on other sites More sharing options...
Gordon A Posted January 21, 2018 Share Posted January 21, 2018 Which primer are you using? I find that Halfords grey acrylic primer sticks like s**** to plastics and brass. Gordon A Link to post Share on other sites More sharing options...
RMweb Gold Corbs Posted January 21, 2018 RMweb Gold Share Posted January 21, 2018 Corbs - You mentioned having a Bachmann Junior that also didn't like glue. Would you be willing to risk a quick squirt of primer somewhere unobtrusive (underside of the footplate?) to see how it reacts? That gpplumy's Bachmann Junior was adhesive happy is, I suspect, more likely to be because it came from a different batch to yours and was moulded from a slightly different blend of plastic. The manufacturers obviously do use different brews for different batches or everyone who's ever tried working on a Hornby Austerity would have experienced exactly the same problem I have. It was specifically one piece - I was trying to glue and on/off switch to the footplate. I had sprayed other parts of the same one with filler primer from halfords and it was fine. The footplate itself was fine with glue in all other places, especially poly cement. Sorry I can't help any further. Link to post Share on other sites More sharing options...
mike morley Posted January 21, 2018 Author Share Posted January 21, 2018 Gordon - the problem with lack of adhesion was with glue, not the primer. The problem with the primer (Wilkinson's own-brand) was that within seconds of being applied it softened the plastic. Link to post Share on other sites More sharing options...
don Posted January 21, 2018 Share Posted January 21, 2018 Mike Halfords acrilyc aerosols and Humbrol enamels are the model boat builders friend,no probs on wood metal or plastic, Have you tried REVELL plastic cement,Humbrol plastic cement,Slaters MEK Pak cement,all regularly used,but wont work on ABS,but i dont think you find any of our models using this. MEK is methyl-ethel-ketone,google for suppliers, All from your local model shop. Don. Link to post Share on other sites More sharing options...
mike morley Posted January 22, 2018 Author Share Posted January 22, 2018 Don, those adhesives are all intended for plastic-to-plastic use and most of the parts I was trying to stick in place were metal. The only exceptions were the plasticard sides of the firebox (Butanone, MEK and polystyrene cement all tried and failed, a tenuous bond just about achieved with Wilko rapid epoxy) and the top and bottom halves of the saddle tank (Ditto the firebox, except that I noticed last night that the Wilko epoxy has now failed on one side) Here is a poor-quality picture taken using my phone to give you an idea of what I was trying to achieve. It was taken about a week ago and getting on for half the non-Hornby parts featured must have become unstuck and been re-fitted since. Link to post Share on other sites More sharing options...
RMweb Gold Dunsignalling Posted January 22, 2018 RMweb Gold Share Posted January 22, 2018 (edited) The advice about washing doing the trick suggests the presence of a release agent on the body (and possibly the castings) that is impermeable to the adhesives and solvents you have tried. It's normal for brass etchings to have a coating to prevent tarnishing and you need to get rid of that, too. After that, it's worth roughing up the surfaces to be joined with a fibreglass brush. For plastic to plastic joints, if Butanone won't work, try Plastic Magic. It seems to have something of a dual action as both solvent and adhesive and has got me out of trouble a few times. If that also fails, there aren't many plastics that will resist cellulose thinners (if you can still get the stuff without a licence) but DO try a very small drop somewhere that doesn't show first. John Edited January 22, 2018 by Dunsignalling Link to post Share on other sites More sharing options...
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