I'm building a power amp on a 3/32 sheet of 5052 H32 aluminum. Most things are attached via countersunk oval head machine screws. So I'm at the ol' drill press, countersinking my heart out, and OOPS!!! -I countersunk a few holes that should not have been. I've got an awfully lot of time in this panel, and would prefer to fill/sand/redrill (or otherwise patch) before I paint -rather than just start over.
Thinking of filling the countersunk hole, then sanding, then redrilling.
I've tried Devcon Metal Patch & Fill (image attached) but the adhesion is terrible. When I redrill using the lowest pressure possible, the plug pops out of the hole very easily.
Would an epoxy be preferable? Liquid Steel or similar, or perhaps one of the epoxy "floor patch" types...?
Anyone have any suggestions for a sandable filler with excellent adhesion to aluminum?
Thinking of filling the countersunk hole, then sanding, then redrilling.
I've tried Devcon Metal Patch & Fill (image attached) but the adhesion is terrible. When I redrill using the lowest pressure possible, the plug pops out of the hole very easily.
Would an epoxy be preferable? Liquid Steel or similar, or perhaps one of the epoxy "floor patch" types...?
Anyone have any suggestions for a sandable filler with excellent adhesion to aluminum?
Attachments
J-B Weld Company - J-B WELD Product Information
Available at Wally-World! I think it is in the adhesive section near the paints
or automotive area.
Available at Wally-World! I think it is in the adhesive section near the paints
or automotive area.
Sounds good!
I really need something with excellent adhesion- there won't be much epoxy/filler/whatever left in the hole by the time I'm done redrilling. I've heard of J-B Weld before, but never used it; sounds good!
AFTER I bought the stuff I tried it occurred to me that I really don't need anything with a metal filler- just something that will stick like crazy, and will not let loose as the aluminum panel heats and cools with use. But if a metal filler provides a good match to the aluminum's coefficient of thermal expansion, that's a good thing...!
I'll drill a few holes in a scrap piece and try various compounds (starting with J-B Weld, probably also Liquid Steel, maybe even a fiberglass-based epoxy) and see how things go.
I really need something with excellent adhesion- there won't be much epoxy/filler/whatever left in the hole by the time I'm done redrilling. I've heard of J-B Weld before, but never used it; sounds good!
AFTER I bought the stuff I tried it occurred to me that I really don't need anything with a metal filler- just something that will stick like crazy, and will not let loose as the aluminum panel heats and cools with use. But if a metal filler provides a good match to the aluminum's coefficient of thermal expansion, that's a good thing...!
I'll drill a few holes in a scrap piece and try various compounds (starting with J-B Weld, probably also Liquid Steel, maybe even a fiberglass-based epoxy) and see how things go.
Plastic Padding Chemical Metal Small from Halfords Price £4.49
This is your ticket. I use it on regular basis, for repairing aluminum tools.
Magura
This is your ticket. I use it on regular basis, for repairing aluminum tools.
Magura
Have you thought about filling with alumaloy. I have not used it, only seen commercials on TV and Internet...seems to work well. Would need access to torch, and grind finished product (you said you're painting correct). Would be fun to try on scrap with similar hole. It looks like you can buy a 1/4 lb. for about $7 on ebay. Here's a link to the HTS-2000 site (one of the "alumaloy" type products): http://aluminumrepair.com/land/index.asp?src=google&gclid=CLbUzf275p0CFQjyDAod7yXtQg
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Welding or patching with aluminum would no doubt be the best... I'm looking for something easy to do without resorting to any tool more exotic than a chainsaw and a big hammer...
Seems like a chemical patch (epoxy, etc) ought to work, but adhesion is a prime consideration, and also temp. stability (the ability for the patch to remain stable after years of operation).
Today I went out & bought a small quantity of J-B Weld and also an aluminum-filled epoxy. I like the way J-B Weld works (it's less viscous when uncured) but the Al-filled epoxy (really a no-name product, an in-house brand of "Do It Best" Hardware stores) seems to adhere better, at least initially- we'll see how it is when fully cured. Both products are in the basement laboratory as I type this, should be fully cured by tomorrow morning.
I'll know tomorrow if either one works.
One of these days I really should get a torch- also an arc welder, and an arbor press and a brake and a shear and a corner notcher and a sheet-metal arbor punch and a table saw and a jointer and a...
<sigh>
More on this tomorrow, after it's cured and I try to re-drill.
Meanwhile, thanks for the suggestions!
Seems like a chemical patch (epoxy, etc) ought to work, but adhesion is a prime consideration, and also temp. stability (the ability for the patch to remain stable after years of operation).
Today I went out & bought a small quantity of J-B Weld and also an aluminum-filled epoxy. I like the way J-B Weld works (it's less viscous when uncured) but the Al-filled epoxy (really a no-name product, an in-house brand of "Do It Best" Hardware stores) seems to adhere better, at least initially- we'll see how it is when fully cured. Both products are in the basement laboratory as I type this, should be fully cured by tomorrow morning.
I'll know tomorrow if either one works.
One of these days I really should get a torch- also an arc welder, and an arbor press and a brake and a shear and a corner notcher and a sheet-metal arbor punch and a table saw and a jointer and a...
<sigh>
More on this tomorrow, after it's cured and I try to re-drill.
Meanwhile, thanks for the suggestions!
To answer my own question (and to put the solution on the record) it seems that one-part metal "fillers" do not work- adhesion is poor and tensile strength is next to zero.
I've tried both J-B Weld and an aluminum-filled epoxy. Both work equally well. They have similar adhesion and both are just a tiny bit flexible when cured- they seem hard when scratched with a file, but not brittle- should be just elastic enough to accommodate thermal expansion.
J-B weld is just a bit less viscous when uncured, making it easier to fill a small hole with less "spillover". It's what I wound up using.
Nice product, that J-B Weld! -Thanks, coloradosound, and all.
I've tried both J-B Weld and an aluminum-filled epoxy. Both work equally well. They have similar adhesion and both are just a tiny bit flexible when cured- they seem hard when scratched with a file, but not brittle- should be just elastic enough to accommodate thermal expansion.
J-B weld is just a bit less viscous when uncured, making it easier to fill a small hole with less "spillover". It's what I wound up using.
Nice product, that J-B Weld! -Thanks, coloradosound, and all.
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