Epoxy Glue and superglue no good brass styrene

The short version......most of what you're talking about is due to poor surface preparation or gluing technique, some may be explained by choosing the wrong epoxy or using cheap shit glues (CA or epoxy). There is a website
Steve wrote:

Well, there is but you have apparently done more research than they.
T2

Any metal, including brass is likely to have an oil coating. One needs to prepare metal surfaces carefully. I wash first with detergent, then a solvent such as lacquer thinner. It sometimes helps when gluing metals to scuff them slightly with fine sandpaper. After that preparation I have had good luck bonding both brass and aluminum to styrene, both with CA and epoxy.
After cleaning, avoid touching the gluing surface with your fingers, which have a skin oil on them. That oil will adhere to metal surface.

Brass surfaces were keyed with coarse sanding stick by Flexifile company. Plastic surfaces given a good brushing with a brass wire brush, also a sanding stick, I was careful to mix equal parts of the epoxy resins. After the brass item styrene bond had been allowed to set overnight, it was tested and found to fail application of slight pressure.
Do note these tests are seeing if a bond is good with a slight pressure to break the joint....as I have brass to compound curve to join,
It was then scraped with a scalpel to cleanse the glue residue, then sanded again, for the next test. Araldite was a recent batch, as the product has a shelf life of 3 yrs, so read the dates on the tube flanges folks. I was careful NOT to handle parts. I shall do some more tests where after sanding, lighter fluid is used to wipe clear the surfaces, incase sanding residue gets the blame. I did what most modellers would do, grab a sanding stick then sand e-w and n-s the part, wipe quickly with paper towel and then glue with just mixed glue.
Thanks for the link, I shall go and read.
Dunlop thixofix is now called Alpha thixofix. As Alpha took over Dunlop glue products. Its non stringing and the same sort of thing as evostick, which does string, so thixofix can be brush painted on, slight chance to re-adjust then press home and hey presto, its stuck.... and someone tells me that items on curves are still there after many years,
Steve

For metal to plastic the site says LePages epoxy glue , sets in 4 hrs,...and JBWeld, similar. For some jobs thats too slow. Trouble is I cannot hold the brass in place that long and because of its odd shape it cannot be clamped easily. There is a real danger of the item slewing round for glues that dont set in 5 mins or whatever, JB Weld's site for the UK is all about mortgagaes ???, US site ok, sounds good, trouble is us UK modellers buy at model shows and B&Q etc, these products require special ordering from the States. Customs duties and carriage costs and so on. We may have UK equivalents of such, we need to think beyond the dumb stuff at shows then , and buy industrial strength glues it seems. Steve

Well, hey, lets look at the problem here. Just how strong does the joint really have to be? When I put railings and deck furniture on a 1/700 plastic ship model I really don't intend to go to sea on the final product. Thus, the final product doesn't really have to be that strong. I find that a dab of white glue (Elmer's here in the states) works just fine for most applications without the problems of making a mess with epoxy. If you don't quite get it right the first time, just pull it off, pop off the little bubble of white glue and try again. Once you have the part positioned to your satisfaction put just the smallest drop of cyano on it to firm the joint. Concerning laminations of plastic/brass or whatever; I haven't tried it but a suggestion earlier in this discussion about heating the brass to help it conform to any contours seems right. If you are after a flat brass/styrene laminate on an important project, I would try a white glue experiment on some scrap parts to see if it would work alright after letting it dry for an hour or so. I can't imagine a model project that would need so much strength as to require anything else.
I do, however applaud the rigor of your process, Steve.
Tom

Try checkign out Devcon's site and look for industrial grade vs. consumer grade epoxies. Also look at Loctite's site and check the industrial grade CA's they make, be prepared for sticker shoch though! Failing that if you're filthy rich and have about a 1 year lead time you could see if DuPont will sell you Y966 film adhesive, used to bond Metglass film to various satellite pieces (note that stuff runs about $50/sqft).
Steve wrote:

JB Weld is a putty like Milliput, I wouldn't use it o laminate. LePages is not very common if it's even still made. Are there areas where something gets glued to the top side of the brass? If so drill a small hole there and use a screw/washer/nut combo in lieu of a clamp, doing that means you only need actual clamps at the edges, liberally apply Johnson's wax plate ot Lee Liquid case lube to the screw and washer so the epoxy won't stick and you can remove the screw.
Steve wrote:

I don't have any words of wisdom about glueing dissimilar materials... But something that may help is working a little bit with the brass before you attempt to glue it. My experience is that most brass sold in hobby shops is 1/2 hard, meaning that it has some spring to it. A way to improve the forming qualities of the brass is to take a propane torch or equivalent and heat the brass until it almost seems to droop. Then let it cool. The brass will now be dead soft and very easy to form. With a tightly fitting piece of brass, the issue with clamping becomes less significant.
Depending on the thickness of the brass and underlying styrene, another way to help the adhesive to do the job is to put teeth on both surfaces. The FlexiFile is all very well to remove surface oxidation, but using the back of the tip of a #11 knife blade to put teeth on the surface is much better. I usually score a cross hatch on the non-absorbent surface to aid the mechanical lock of the adhesive. Since you have two non-absorbent surfaces, score them both.
With a well fitting piece of brass and a mechanical lock, even white glue holds amazingly well.
Just a thought--
Rick