Methods for adhering painted polystyrene (?)

[Speedfreak]

Hello, I have avoided this dilemma for quite some time by simply using Microscale Krystal Klear for most of the parts on my recent models. For the most part it works very well, the biggest drawback being the time required for set-up. So, if there is a part(s) that requires quicker set-up to hold, it's not that great.

Back in the day I would paint parts and then scrape the paint off the contact points with exact-o and apply cement, works very well but a lot of time spent scraping and possible deformation of parts. 

And then there is the ' white glue' on contact surface 'before' painting,  but , I've never been comfortable with that method, not sure why.

What method(s)/ materials, do people use for adhering painted polystyrene surfaces? (and yes, super glue will melt Tamiya Lacquer!)

Reveal your secrets here! Thanks!   

[Jantrix]

I only use CA glues or white glues on painted parts. No scraping of paint required.

[Bainford]

I pin everything mounted to a painted body. I usually use 1/32" brass rod to make pins, but also use .025" and 1/64" rod for pins where the small contact point of the object to be attached warrants it. All gluing is done on the inside of the body shell, super strong and zero visible glue.

I have a Tamiya Mini Monte Carlo racer with the roof rack for the spare tires. The rack is pinned to the roof at each of the four roof rack legs. A fellow at a contest once remarked that the attachment of the rack to the roof must be very weak, given the lack of visible glue. He almost had heart attack when I reach down and picked up the model by the roof rack and shook it around.

[peteski]

I do what you don't like doing (mask the plastic before painting, scrape the paint off, or pin parts), so I don't have much advice to offer.  When using CA glue on painted surfaces, use BSI brand accelerator (applied with a precision applicator, like a Microbrush). If the CA glue doesn't set on the painted part for a while, it will melt the paint and not make a good joint.  The bottom line is that no matter what you try, the strength of the glue joint will only be as good as the weakest area in the joint (usually it is the paint).  There is no magic trick to make gluing painted parts easier.

 

Edit: Actually, I forgot epoxy (because I don't use it often). But since Steve mentioned it in the post below mine, epoxy it also good adhesive for painted parts. It will not melt the paint, but it takes a while to harden.  I'm ore of a CA glue and accelerator addict - I like my glue joints to be instant (in most instances).

Edited August 16, 2018 by peteski

[StevenGuthmiller]

It depends on what I'm gluing & where, and what type of bond is necessary.

I get by with CA glue, clear parts cement & 2 part epoxy.

Occasionally I use a little UV light setting glue for mockup, tacking & glass installation.

I never scrape any parts in preparation for gluing.

I will also pin parts when necessary.

Especially parts fastened  directly to the body such as mirrors or antennas.

 

Steve

Edited August 16, 2018 by StevenGuthmiller

[Speedfreak]

Hey, thanks for the responses! I'll try some accelerator with CA Pete, never done that. Pinning seems to be the method used by most, I do that sometimes but only as a last resort, and , with things that I know will be a problem, like headers. What I'm actually working with now is the rear suspension on a Revell USRRC Cobra,  so pinning not really an option.  Ok you guys, you've given me plenty to think about and try.

Thanks,

Gene

[Matt Bacon]

If you can find this stuff:

https://www.amazon.com/Evo-Stik-Serious-Strong-Adhesive-663671/dp/B00ID68T5Q/ref=sr_1_6?m=ADP0WGXA9SAVO&s=merchant-items&ie=UTF8&qid=1534452225&sr=1-6

I'd recommend it. It's not superglue (I don't know what exactly it is, TBH) but it will stick painted parts together and keep them that way. It has no effect that I've found on paint including enamel, Tamiya acrylics in a pot, Tamiya spray (TS) paint or 2pack clearcoated Zero paints. It has good "grab" (a small dot will hold the weight of a mirror on a door as soon as you put it in place), starts to cure in a few minutes, is stuck firm after an hour or so, and reaches full strength after 24 hours. If you "catch" the mirror after 24 hours, most of the time it won't come off (you really have to peel the parts apart), and if you do pull them apart 99% of the time it comes off the surface with no damage to the paint. It's pretty tough, gap filling, and goes exactly where you put it with a toothpick or bit of wire as an applicator.

The only drawyback is that you really do need to clean the nozzle and lid each time you use it, so you get a good closure without gluing the nozzle and lid together. It will cure in the tube eventually if there isn't a good seal at the top.

best,

M.

[BigTallDad]

I do the pinning thing too, but I use styrene rod (available in very small diameters) instead of a metallic pin. Pin the part (mirror, etc.) using CA or solvent-based cement and paint it if need be; after the body is painted, drill a hole for the pin, put a dab of medium CA in/around the hole, and attach the part. The medium CA allows you a brief "work time" to ensure the positioning is correct.

[peteski]

20 hours ago, Matt Bacon said:

If you can find this stuff:

https://www.amazon.com/Evo-Stik-Serious-Strong-Adhesive-663671/dp/B00ID68T5Q/ref=sr_1_6?m=ADP0WGXA9SAVO&s=merchant-items&ie=UTF8&qid=1534452225&sr=1-6

I'd recommend it. It's not superglue (I don't know what exactly it is, TBH) but it will stick painted parts together and keep them that way. It has no effect that I've found on paint including enamel, Tamiya acrylics in a pot, Tamiya spray (TS) paint or 2pack clearcoated Zero paints. It has good "grab" (a small dot will hold the weight of a mirror on a door as soon as you put it in place), starts to cure in a few minutes, is stuck firm after an hour or so, and reaches full strength after 24 hours. If you "catch" the mirror after 24 hours, most of the time it won't come off (you really have to peel the parts apart), and if you do pull them apart 99% of the time it comes off the surface with no damage to the paint. It's pretty tough, gap filling, and goes exactly where you put it with a toothpick or bit of wire as an applicator.

The only drawyback is that you really do need to clean the nozzle and lid each time you use it, so you get a good closure without gluing the nozzle and lid together. It will cure in the tube eventually if there isn't a good seal at the top.

best,

M.

Interesting.   Here is a link to the info about this adhesive: https://www.rapidonline.com/pdf/87-4030_v1.pdf

It is not a CA glue - that is correct.  It is a moisture-cure glue (the Polyurethane adhesives from Gorilla Glue are also moisture cured) but this one does not seem to be urethane based.

To quote the above mentioned document:

- Solvent-free, odourless, safe to use
- High strength – lifetime bond
- Extreme temperature resistance

EVO-STIK Serious Glue is a high performance; single component, moisture curing, Modified Silane (MS) Polymer based adhesive. It will bond most surfaces even if both are impervious. The product will bond damp surfaces and may even be used underwater. It has very low odour, cures to form an elastic rubber, with almost no shrinkage and low hazard; it does not contain any water or solvent, making it ideal for bonding foam polystyrene. EVO-STIK Serious Glue bonds to most surfaces including wood, concrete, brick, plaster, glass, ceramics, metals, rigid pvc, grp, fabrics and foam polystyrene . It is ideal for fixing and repair jobs inside and outside the home, in the garden, for cards and boats and for hobbies and crafts (EVO-STIK Serious Glue will not bond to polyethylene and polypropylene materials).

I might just add this one to my already-extensive arsenal of adhesives.  I wonder how it works in really dry climates (since it needs moisture for curing)?

[Speedfreak]

That glue sounds worth checking out, thanks for the info! I have made progress on rear suspension, hopefully enough progress. Great info in this thread. Thanks to all who responding.

Edited August 17, 2018 by Speedfreak