Aluminum brazing

[nama]

So the brazing rods arrived yesterday and today I had a chance to try it out.

braze.jpg (36.66 KiB) Viewed 7343 times

Some observations:

- It's very hot. Don't be fooled into thinking you are dealing with solder temperature even though it looks identical when molten.
- After the braze cools it can leave very sharp burs which can cut skin, as I found out as I now have a gouge out of my thumb.
- the aluminum after heating and cooling is now VERY pliable. I think I need to reheat the area again and do a rapid cool with a dousing of cool water to harden the metal.
- The braze seems harder to file than the base aluminum
- Although the braze when molten has a lot of surface tension, there is a limit to the maximum size hole you can bridge, as I found out.
- if you put the braze rod down, don't later pick it up by the wrong end!

Some small problems and small injuries, but overall I think things when ok. The pliability of the metal is a bit worrisome. Hopefully it's easily fixed.

Next steps is to put a small bridge of aluminum in the big hole that couldn't be filled. Try reheating the metal and rapid cooling it. Spend some time with a file (not looking forward to that).

Philip

[dave]

Interesting you mentioned it. I was recently looking at this site. Is this really an improvement over other brazing materials, or is it just marketing?

Dave

[nama]

My understanding is that HTS2000 is basically the same as other aluminum brazing rods that are available.

[nama]

You can see how the fix is progressing here:

Before brazing

case1.jpg (39.88 KiB) Viewed 7343 times

After grinding

case2.jpg (51.78 KiB) Viewed 7343 times

After grinding

case4.jpg (44.99 KiB) Viewed 7343 times

Not as easy as I thought it was going to be, but regardless, I'm making some good progress. All braze has now been ground down using a hand grinder (what a lifesaver. I couldn't imagine doing it by hand as the braze is much harder than the aluminum and very difficult to file). Next step is to just tidy up any rough grinder marks and then send it off for sand blasting and powder coating. I also need to build a bracket to mount the new switcher power supply. Hopefully it should be all ready for assembly just in time to install the new floppy drive card (hint hint).

Philip

[dave]

It looks fantastic.

[nama]

I finally got the case sand-blasted and powered coated. Next, build everything up.
I will post some pictures of the final build.

Philip

[dave]

That looks amazing. I actually prefer this color to the original appearance. I do remember some variation in color even back in the day. I remember seeing computers with a slightly more matte lighter shade back then, and thinking it was a good look.

[nama]

I didn't have much choice when it came to powder coating colors with a hammer like finish. It was either variants on bright primary blue, or this slightly grey blue. I think the colour I chose, although not original, looks very good indeed.

I'm now half way through the build, and should have have it all together this weekend.
I'll shoot pics of the inside and outside so that you can see how I made some simple adaptor brackets so that I could mount a modern switcher power supply inside (if you recall, I received the machine minus a PSU) while not having to resort to making any unnecessary holes in the OSI case.

Phil

[nama]

FINISHED!!!!

[nama]

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