best way to affix etch brass flat sheet to plastic ?

I'd approach this as if I were applying a formica laminate to a board. Contact adhesive to both surfaces (I like 3M CraftMount, nice and thin and good adhesive qualities), line it up on "gluesticks" (thin lengths of wood) over the deck, remove one of the sticks, tack that end down then work your way along. Rolling the brass flat both ways first would seem to be a good idea to me too. This is only a suggestion, I have no idea if it's going to work, so don't go blaming me...

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White "Elmers" glue is your friend. Gives plenty of time to adjust and is suprisingly strong. Use enough so that it squeezes out and then carefully clamp so that the etch is not marred. Problem with contact cement is that you just get one chance.......

Tom

White glue on a plastic to metal flat joint? First of all, neither material is porous or permiable to water. And Elmers glue sets by evaporation. It won't dry for months! And even if it did driy, it would not be a permanent joint. Neither plastic nor brass are porous enough for the glue to develop a good mechanical bond.

I would say that 5-minute or even 1-minute epoxy is your friend here. Just make sure to clean both surfaces well. Epoxy will give you a permanent bond.

A thin CA adhesive would also work well here. Just align both parts untli your happy and then apply some thin CA to one of the edges of your brass deck. Wicking action will spread the CA under the brass. It should set instantly. But for a good measure I would apply tiny drop of accelerator for a full cure. I love that stuff!

Peteski

Hi Peteski, I put my thinking cap on, having had no reply before time to glue, and came up with the idea of capillary action just as you suggested and it worked. Used Loctite thin CA, and Zip Kicker accelerator. Trouble is you need one hand holding boat at an angle to see what you are doing under the light, another with finger nail or tool pressing down just that part of the brass to get a small enough gap to get capillary action (wicking) and the third hand applying firstly the glue then the accelerator ! I used strips of masking tape to free up one hand, even so there were parts that needed a push down.

Pre annealed the brass by heating it with cig lighter flame and leting it cool naturally, flattened better but not dead flat.

Shall try the 3M craftMount, as is said, trouble is one shot and its there, so alignment vital,...scary !

5 min or 1 min epoxy, did consider that, hate the gooey aspect, wish they did one that was more the consistency of thick gap filling superglue thats starting to go odf or shelf life too long !

Elmers, yes...did wonder about it ...not my obvious choice as needs evaporation. Tom, have you used it for such and how does it work in that case ?

Also found the s/glue that got on top of the brass would flake off if poked with a scalpel tip, usefull to know and do, but will it come of the u/side, hope not !...I roughed up the brass there to key it and that should help, uppers may have had finger grease though not much. Another trick there would be to apply maskol masking fluid to avoid spoiling upper detail.

Wonder if such findings and methods get put into a how to type database, needs it !

Steve

I've also found that watch crystal cement works well, as long as the mating surfaces are flat, and you're gluing etch to unpainted plastic (which is how it should always be done, IMO). Watch crystal cement will provide a relatively long working time but you may need to clamp a large piece in place to insure it sticks flat.

My problem has alway been that I am "gluing" PE parts (railings, antennas etc) that have been painted to decks that also have already been painted. I honestly haven't tried a PE/plastic laminate with white glue but based on a current project (eye-rings in the plastic deck of a plastic Cutty Sark), the white glue makes a relatively strong bond without the mess of puting CA into a joint between 2 painted surfaces. My method of attaching PE parts to the deck of a 1/700 destroyer which seems to have worked fairly well is to shape and dry prefit your part and then use a very small amount of white glue to "firmly" position the part. Note that the white glue give you substantial adjustment capability to get the PE part on there just right. Let the white glue set up for 15 or 20 minutes and then go back with the smallest quantity of CA that you can apply to the mating edges. This method lets you actually touch the PE parts with your CA applicator without moving them from the just-right position. CA will even make the white glue temp bond stronger. I I were you and I I understand your project well enough, I would give the white glue a try with a spare piece of brass and a flat piece of plastic to try it out. As said, alignment is easy and if you mess it up you should still be able to slit it apart to try again. If you succeed, some CA could be wicked into the seam to make it seem more permanent.

Tom

"Steve" wrote in message news:T3cNh.1383$ snipped-for-privacy@text.news.blueyonder.co.uk...

Hi Steve, I'm glad that you've found a workable method. I use various shapped needle applicators (home made) for applying CA glue. So, I don't have too many problems with the glue marring the top exposed surfaces.

If the underside of the glued plastic surface is accessible, I have another trick up my sleeve to get clean CA joints. I drill some holes in the plasitc part. Very slightly moisten the brass part's bottom surface with CA accelerator. Place the brass part in it's final resting spot. Then apply the CA into the drilled holes under the brass part. Use thin CA. Capilary action will spread the glue under the brass part and the accelerator will harden it instantly. I LOVE CA GLUE! :-)

As far as epoxies go, they aren't really that bad. Even if you need to hold the parts together for 5 minutes, it is not the end of the world - I've done it. Listening to radio or watching TV helps here. And remember - if the joined pieces are flat, you need to apply very little epoxy. That way, it'll not ooze out on you. I usually take a toothpick and just dab several tiny dots of epoxy on one part (not near the edge), then just join and squeeze both parts. The pressure will spread the glue dots. If parts are flat you usually dont' even need to hold them together. The viscous epoxy will hold them perfectly aligned. All you need to do is leave the appembly alone for a while so it has time to set.

Did I mention that I love CA glue? :-) Peteski

Hi, some interesting methods and ideas here and many thanks, do hope such get stored in a database. There never is a book on this levl of modelling, always state the stuff we all know. Stan Catchpoles modelling guide was good, a sort of magazine extra many years ago in the UK.

I like the idea of small blobs of epoxy rather than spread about, ensure blobs not near and holes that go all the way through the brass. It has that adjustability which is good. It could go on the brass part, that way I see how near to holes I am. I also like the idea of small recepticle holes for CA, though in fact blobs sitting on undrilled plastic would do just as well. I dont see my Zip kicker accelerator staying wet for more than a few seconds if that, so there would be a mild panick to position part and its instant bond so scary. Also if superglue blob touches brass with the accelerator on that part of the brass, I can imagine the glue forming a skin then setting before its had a chance to get at the brass, rather than do its bit then get set. Perhaps better to have no accelerator, some gap filling slow set CA as spots on the brass underside, then position it and fine adjust for those few seconds. I shall try to find some slow set superglue, it all seems fast somehow ! (UK modeller for any suggestions by the way) White glue as a positioner perhaps, but under a large panel, still not sure of it drying out. I have something called tacky wax by Deluxe materials, in red plastic tub 2inch dia, with pull off lid. wax adhesive for holding miniatures in place. Allows repositioning, remove with warm water and soap it says. Few dabs of that may be better, else why have I bought it I wonder. Not used it yet so shall give it a try. Tom, as its instant, you might like to try that also.

Having gone for the superglue at edges/capillary action method, and into any holes in the sheet that would accept it, I used a #10 curved blade, some loctite runny superglue and seemed to get a good bond. However when filing down the filler up to the shet, I made the mistake of upwards strokes, as I obviously was on my last stroke to be at the brass it caught the edge, and up it came !! a little bit, so glued it down again, ...use downward strokes that will not lift the brass ! I am to go for the araldite spots on the next one ! Steve

Looks like you are evolving your own techinques. Excellent!

Dots of epoxy should also work. And epoxy adheres to brass better than CA. Roughing up the brass part with some sandpaper will also improve the bond. But I don't think anything would withstand upwards stroke filing.

Peteski

Well I have experimented with a new purchase of Araldite and a 5yr old pack pf Devcon 5min epoxy unused. Both dry rock solid, can't poke a mark into them on the mixing palette. HOWEVER..... Both come clean off styrene sheet with mild testing, they wont glue bras to styrene, or brass to brass, or styrene to styrene,...takes some believing, but tests prove so, apply mild force and pop, perfect release, untarnished plastic.....so useless for anything that may put up a slight fight, curved brass that needs to go onto a similar shape as I have the task of doing.

I try a brand new pot of Loctite superglue, same thing, brass comes off styrene. and brass comes off brass. Yes all were roughed up beforehand.

I am amazed at these findings, we get told to use CA for ebrass, well, if its going to see any spring in it then forget it, its a whisker away from coming adrift. I have even needed toremove part of my decking and it couldnt have been easier, so grateful for its uselessness there !

Dunlop Thixofix has been suggested for sheet metal to plastic curve. Not a B&Q or Focus product though, they sell domestic crap, usual story, anything worthwhile and look to an industrial source. I bought Evostick Liquid nails, goes on like toothpaste, performs like toothpaste !...absolutely no 'Instant Grab' as it claims on the label, brass to plastic, zero grab. It says Ultra |strength Liquid nails...its rubbish for brass to styrene, or styrene to styrene. You can flick it off styrene !

We need something that modellers can read to avoid these pitfalls, or am I the first to actually experiment and see what works ? Nowhere do I ever read that CA is no good for brass to brass if likely to have to withstand any slight force, brass onto a curve etc, or bend force.

How do we get such facts into the FAQ ?

Steve

Funny...I've been using etch since the old Model Technologies days, never build without it now, and I've never had a problem getting brass to stick to raw styrene using CA glues...I've recently discovered one I like which is formulated for tires (it's black) and presumably has a bit more flexing capability. (I plan to use it on the etched fore and aft deck end plates on my current 1/72 U-boat.)

Sounds like you have a contamination problem to me - either a mold release is still present on your plastic parts, or something in your work area is getting into your joins. You could also try wiping the contact side of your brass parts with alcohol or vinegar and then alcohol; the vinegar should etch the smooth surface slightly and give it a bit more "tooth"...I think it will also turn it black...scrub with a bit of steel wool in that case to remove the soot. You may also have enough glue residue built up on your parts after so many trials that nothing will stick now...

Somthing else you could try is 3M spray on contact cement, or a similar brush (which I believe is water soluble while wet...) on contact cement used for applying sheet ply to foam R/C aircraft wings. You apply the glue to both surfaces, allow them to dry, and then press into place - be warned, once placed these joins are permanent; you get no working time, and no second chance at laying the part. 3M spray-on adhesive is particularly sticky...and a bit thick, both are pretty flexible. Good stuff for sheet-work, though.

I agree. I use lighter fluid (Naphta) or 99% Isopropyl alcohol to clean/degrease styrene before gluing. Same can be used for cleaning brass surfaces or you can go even stronger and use acetone or lacquer thinner. If you still have adhesion issues, roughen the glued surfaces with sandpaper.

Glueing a flat brass part to a curved styrene piece so that the brass is under tension, you're asking for trouble. You might want to anneal and pre-bend the brass part to a curvature matching the plasit part.

Peteski