Hmm ... what about soldering brass metal screws to the brass front (go for a thicker brass -- say from places which supply the brass for engraved nameplated on trophys), fit the screws through holes drilled in the steel backing, and spin brass nuts onto the screws. (Use decorative ones if you figure too many people will be looking at the back of the plate.)
Is there a reason you use such thin brass for the task?
Hmm ... another possibility is to spin the brass onto the steel, folding the edge (a bit of excessive diameter) over a fairly sharp bevel on the steel. Clamp the brass to the steel with a live center and a wood spreader pressure plate while you do this -- and turn (bore) off the ID after the OD is rolled over and gripping nicely.
The solder working gives me an idea. Try heating and cooling a sample, then doing the surface prep and bond. Might be something on it that burns off or evaporates before it gets to soldering temperature.
I still think the answer is to use different epoxy. But while you are trying different things, try heating a sample of the brass so you get a relatively thick oxide coating on it. If you use a torch to do this, then clean with some solvent. If you use an electric oven, then do not bother to clean it. I think you will find that the oxidized brass will bond better. Sounds crazy, but as long as you are trying different approaches...................One experiment is worth a lot.
The differences between the brasses may be how much copper is in the alloy.
" snipped-for-privacy@krl.org" fired this volley in news:2fe27c7c- snipped-for-privacy@k39g2000yqb.googlegroups.com:
I'm thinking it may be lead that's giving you the problem. Even high- quality enamels fail to adhere to lead. When the paint film cracks, the entire layer sheets off.
Lead also tends to migrate to the surface of leaded brass during forming processes.
It is not, as I have demonstrated with those other pieces. I suspect that I do not understand the mechanics of peel, however, the peel alone would not explain the failure of the glue to adhere to brass while adhering tenaciously to the steel side of the joint. Does it make a difference if it is the side that is peeling as opposed to the side it is being peeled off of?
Anyway, as this is getting old rather rapidly, two more tries:
1) A slightly thicker (0.015") brass, purchased in the same shop as the
0.006" way back. Same treatment but this time I did not run a steel-to- steel control. Once the peel started the whole joint unravelled with little difficulty with the same appearance, i.e. no glue stuck on the brass side.
2) Most important: I found the piece I started experimenting with originally. Looks like the one on flickr except the brass face is battered through rough handling. a) I found a small part of the periphery that was not completely stuck down. I got a tip of my pliers on it and tried a peel. To my surprise after initial 2 mm or so there was *no* peel! The brass was well and truly stuck to the steel. On the separated part you see bits of glue on both sides of the joint. I am trying to remember what I used at the time and keep coming up with Household Amazing Goop: The stuff is horrible to use, very thick and hard to spread. I understand that it may be of the same family as E6000. b) To investigate the properties of the brass foil without the peel effect coming into play I thought I had a unique opportunity here: The brass (which, BTW is from the same roll as all the other bits I have been experimenting with) was well and truly stuck to the steel and thus rigid. So I made another joint with the JBWeld using the existing piece ending up with a sort of steel sandwich. Lo and behold, after 24 hours I could not separate the joint by hand alone! After doing so with the help of a vise, the joint looked as all the others, i.e. all the failure of adhesion was on the brass side.
Thus one must believe in the magic properties of the Household Amazing Goop. I wish I remembered how long I left the piece to cure at the time. The E6000 after 24 hours was no better than the others. Pity, as it is damn sight easier to use than the Goop.
I have no reason to dispute what you say about the JB Weld, however, having been playing with glues of all kinds for some time I find that on metal it gives the most consistent results. I have not tried to cure the other epoxies for a week as someone suggested. Even if the result improved why bother if JBWeld will do the job quicker (in fact on most surfaces a medium density cyanoacrylate is even quicker and the strength is comparable - I use it when repositioning is not an issue).
As to the possible heat effect, the face popped off while I was cleaning up the rim of the glued up piece in the Taig. I doubt there was a significant heat generation involved.
There are now several compelling reasons for me to use thicker brass for this in future: Less likely to peel, less sensitive to damage etc.
I shall do one more trial: Brass-to-brass using the Goop and E6000. I might let them cure for a couple of days.
The JB Weld may work better because there is less epoxy. My understanding is that epoxy destroys the oxide layer and therefore results in no adhesion. So a thicker layer of oxide or less epoxy may work better.
The clear winner was the Household Amazing Goop. It was not subtle. I wish that stuff was easier to use! I am left pondering what black magic chemistry is involved here...
I had the sole of my last pair of desert combat boots come loose at the toe. Gooped it up good, put a brick on it for a couple days and 2 yrs later..Im still wearing it.
Gunner
One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch
Like the laminate adhesives, Household Goop is highly elastomeric. It's a polypropylene/solvent adhesive. Those adhesives aren't especially strong in tension or sheer, unlike epoxies, but they're the most peel-resistant types.
Most likely, it's a peel issue you were dealing with.
On Fri, 16 Jul 2010 18:18:13 -0700, "Michael Koblic" wrote the following:
Warm it and the applied pieces before use, Mikey. Latex paint and caulk are the same way. The warmer they are, the easier it is to work with 'em.
I'm really surprised that the Household Goop outperformed the E6000. I have tubes of plumber/household/shoe Goop and E6000, and have almost stopped using all but the E6000. It's a bit thinner and easier to use, and it grips everything I've tried it on, including bookbindings, quite well.
Coming in late, but have recently tried the new West System GFlex 655K thickened epoxy with good luck on Aluminum. It might be a good candidate for brass, too. They claim it is "toughened" and has some flexibility to handle stresses. Even can be used to repair aluminum boats and cures underwater.
A call to Gougen Brothers might yield some good ideas. 866-937-8797
That sounds like a possible candidate. In high-tech uses, the "toughening" of epoxy is an adjustable thing that suppliers do my mixing in various amounts of other polymers. JB Weld, in fact, contains some other polymer, which is described in general category terms in their MSDS. In general these trade off a small amount of sheer/tensile strength for greater peel/cleavage strength.
The Gougeons have wrestled with cleavage problems (a similar, less extreme issue than peel) with epoxy for over 40 years, and they're fastidious about their products, so it's worth a try.
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