The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Stu55Flash on 29.05. 2010 23:52
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Has anyone experience of using this to fill deep gouges on side casing. What do it look like when polished - is it still visible?
Stuart
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Hello Stu!
I tried it on the primary cover of the A7 which had some deep scratches and had been welded by the PO, leaving some large pores on the outside.
The problem is that it doesn't really match the tone and appearance/shine of the alloy, leaving clearly visible darker and duller speckles and spots where applied.
I ended up searching and buying another cover however.
But still quite useful for sealing faces etc.
Best wishes, Markus
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Lumiweld is a zinc based alloy that diffuses into aluminium.
Basically it will appear to have a blueish tint to it and as such will be noticeable.
OTOH it works very well and can render a "scrap " part useable.
What is actually going on is that you melt a lump of the alloy on top of the oxide coating on the aluminium part.
You then scratch through the tough oxide coating and that floats to the surface.
The lumiweld and the parent metal then dissolve into each other to make the repair.
As zinc alloys melt much lower temperatures than the Al-Si alloys you don't run the risk of melting your part defore you fix it.
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i have used it connecting a stub on the rear tappet cover to make an additional breather and found it quite easy to use. I did the welding on the inside so sorry i don't know what it looks like when polished. The authors above seem to be very well informed
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Took two photos of my old cover so that you can judge for yourself whether you could live with it or not.
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I used it to repair lugs/threads on a crankcase for an AMC timing cover a couple of years ago, and it did do it. But I found it hard to use in areas which had been oily over the years and I didn't find the 'abrader' an easy tickling stick to make things do what '54A10 so accurately describes although it worked well under test on clinically clean bits beforehand. The colour didn't bother me being on the inside as it were, but it's a bit different from the parent metal. In its favour, it took to the alloy, it drilled, it tapped and it is still holding some 2BA screws where they should be after a good few thousand miles - so it's tough enough to take an absurdly small fine thread (that BSA would never have used for such a thing).
Haven't tried it for cosmetic repairs though - MG's pix are better guides!
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i think it is really good to show the history of your work
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Experiments gone wrong also can have some didactic effect. *smile*
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Steady on MG - didactic - I had to look that one up *smiley4*
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"There's more to be learned from failure than from success."
-- Soichiro Honda
David
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"There's more to be learned from failure than from success."
-- Soichiro Honda
wink2 History did prove him right I guess....