TechnoWeld Test

Do you remember those early days of 'biking when a clumsy moment with a spanner knocked off one of your FS1E's (read Bantam if you're my age!) cylinder head fins. What about the day the tarmac took a great chunk out of your engine cover? I recall my feelings being a mixture of anger and helplessness. If you knocked off a footrest, you could usually get a mate to weld it back on for you. Any other part could be usually fixed with a bit of body filler. Aluminium though; nobody could fix that, could they? Well, they could if they made aeroplanes or racing cars for a living, but I didn't meet many of those down on the farm.

Techno-Weld supply aluminium repair kits which could save many classic motorbike parts from the scrap pile. The kit arrives as a tube containing the 'rods', a stainless steel brush for cleaning the work piece, and abrader for assisting the fusion process, and a small booklet of instructions and tips . Techno-Weld is billed as 'The Ultimate Easy-to-Use Low Temperature D.I.Y Aluminium Fusion Welding Kit'. Quite a mouthful! I had a rummage on my shelves and came out with the 'Ultimate Test' for the 'Ultimate Easy-to.......'. A knackered 250LC engine side cover ought to give the system something to think about . Now, Graham Newman, who makes Techno-Weld, urges caution and suggests that you try a few test pieces before venturing out on serious bike mending. I come from the school of thought that says reading the instructions is so much more informative after you've made your first mistake, so here goes. The first job is to clean back to bright aluminium. I removed the paint with heat and wire brush, then used the supplied stainless steel brush to finish off .

Next, you need some heat. In this case 'size is everything' because the Techno-Weld rod must be melted by the surface of the work piece, not the torch flame. The process is more like soldering than welding, as Techno-Weld melts at 380oC. I have a large butane gas torch , which is OK for most jobs, but it is possible to get some heat into a large part by popping it in the oven. It's probably best to bribe your partner to go shopping at this stage.

Elsie's crankcase cover was duly heated with the torch until the rod would melt against its surface. It is tempting here to put the welding rod into the flame, but the weld material just balls up and runs off the work piece. Once the rod can be melted against the work, you can 'tin' the surface, just like soldering. There is no flux to play with but a stainless 'abrader' is provided to break down the oxide coating which forms on aluminium. Once you have a bright molten pool of Techno-Weld just rub through it to break down the oxide layer. It doesn't need much. Once the surface is broken, Techno-Weld will seep under the layer and break it up.

Once the job is tinned, more Techno-Weld can be applied to the surface. The hot Techno-Weld can be moved around by the abrader. If the weld sags down it can be left to solidify then reheated to reposition it. I bit off a little more than I could chew (in the interests of science, of course) with the Elsie cover. My gas torch was a little borderline for heating the piece and the shape is a little awkward, too. I did, without a great deal of difficulty, succeed in filling some serious gashes in the casting, with the Techno-Weld kit. Once the Techno-Weld has cooled, it can be filed and sanded, just like the parent aluminium. It is a little harder and brighter than most Japanese die-casting material, but polishes up very well.

Just to have a go at something a little more manageable, I pulled a couple of bits out of my scrap box to see how easily Techno-Weld can be used for joining parts . This time, my gas torch was well up to the job. I cleaned up both pieces and tinned them with Techno-Weld. The small pieces heated up rapidly and it was easy to maintain the temperature while I built up a fillet around the join . Magic! Almost as easy as using 'ordinary' soft solder. Just to convince myself that I had, indeed, joined the pieces, I let the parts cool, then gave them a good whack with a hammer . One of the components bent, but the Techno-Weld join stayed intact.

Having played with the kit, I sat back and read the instruction leaflet. This is really the best part of the whole kit. The instructions contain a wealth of practical experience for beginners and advanced users alike. I can only add one piece of advice to Graham Newman's instructions. Don't pick up any bits that you've just been welding. I've got a feint print of a 250LC water pump housing on my thumb!

Being just a tad cynical, I get a bit worried about claims made for 'wonder products'. The Techno-Weld kit, though, lives up to its claim and brings practical aluminium repair and fabrication into the home workshop. I've just discovered that my 'scrap' corner is full of useful, repairable motor bike parts.

Supplier

Techno-Weld Ltd
Aston Works
Back Lane
Aston
Oxon OX18 2BX
England
Tel +44(0)1993 851028
Fax +44(0)1993 851036

Also available from Machine Mart

In the US try Caswell Plating

Video Skill-Guide To Gas Welding



Availability: Usually dispatched within 24 hours

Edition Details:
PAL format
 Colour, PAL
 ASIN: B00004CM1V
 Catalogue Number: PPV3118

Leading motoring and DIY author Lindsay Porter guides the viewer through all the steps to successful oxy-acetylene or 'gas' welding. He covers welded joints, brazing and cutting, plus personal safety. Lindsay completes the programme with hints and tips on handling car bodywork repairs.

Useful Books on Welding

Welder's Handbook : A Complete Guide to Mig, Tig, Arc & Oxyacetylene Welding Richard Finch; Paperback
Practical Welding Stuart W. Gibson MSc DME C Paperback
Basic MIG and TIG Welding I.H. Griffin; Paperback