There're a few forlorn parts kicking around the workshop at the moment that are fashioned from aluminium and suffering grievous injury. The most piteous of which is a Campagnolo rear mech, its presence haunting as it was I the one who metered punishment to it. I had filed away at it in an attempt to adapt it to fit a Benelux rear hanger. The experiment was unsuccessful and the mech seemed to be useless, too good to throw away and too costly to repair economically.
With a couple more projects in mind (in particular the fashioning of a custom bash plate for the Redditch Bullet trials project) it seemed a good idea to try a home repair. There was not really much to lose from the attempt. Lumiweld has been around for a good while and I figured that if it was still on the market it must be at least OK.
The Lumiweld kit comprises rods, a small wire brush and instructions. The concept is that it makes a fused joint with the rod melting at a lower point than the aluminium surface and the process can be done with a regular blow torch as the heat source.
The instructions recommend pre-heating the item to be repaired in an oven, probably a good idea if you have a larger weld to attempt on a big item, but as I was aiming for a small blob to be attached to a small item I decided to go for the blow torch all the way. Also recommended is practising on some scrap first, this I did and the results were good. Simply prepare the item to be welded by cleaning it and then giving it a going over with the wire brush. Next step is to heat the item to be welded, you can test the rod against it to see if the temperature has been reached. The instructions recommend 'tinning' the surface as you would with a solder. In fact the whole process is pretty much like soldering and if you are competent at this then you would find lumiwelding easy.
The aim of my job was to build up a weld that I could then file down to shape. Lumiweld isn't particularly good at this as applying further heat just melts the weld you have already applied. However for a small build up it was successful as the surface tension of the material allows a fair sized blob to grow before it runs.
Once cooled down the Lumiweld was found to have fused properly and could be worked just like aluminium. I filed it down and effected a pretty good and barely visible repair. Overall a good product, one that does what it says on the tin and one that will allow easy aluminium repair and fabrication in the workshop.
|Lumiweld rod, wire brush as provided in the kit and the|
subject to be repaired.
|The test weld.|
|The firs stage - 'tinning' the area to be welded.|
|Beginning to build up the weld.|
|The weld built up and with the filing down to shape just started.|