Cold welding aluminium

whiteoaks7

whiteoaks7

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www.seasolutions.co.uk
I have some ali components to weld together. Some time ago I almost used a 'system' to bond/weld together a stanchion which seemed ideal - it was sold as a 'cold weld'. I ultimately didn't need it then but I do now and, of course, have lost the details. Anyone know a good product that will reproduce or exceed the strength of the substrate in a straight tensile pull, which can be applied cold, plus used in the marine environment with temp range -10 to +50C? I know there's one out there somewhere...
 
Hi
I have seen this stuff advertised. It appears to be little more than Araldite with metal filings in it. A bit of a con I think. It is possible to cold weld metals but they have to be perfectly clean and very great pressure must be applied.
 
Capt Courageous is right, there are various 'cold weld' products on the market for which the makers make extravagant claims: Chemical Metal, Chemical Steel, Super Steel, JB Weld, Quik Steel being some of the more popular products. Basically they are all the same, either polyester or epoxy resin reinforced with usually aluminium particles. The makers make pretty extravagant claims for them, but basically they are just plastics with metal filings. Good enough in the right application, but totally dependent on how well prepared the surfaces are. JB Weld is nothing more than straight epoxy, and in my experience one of the best fast setting epoxies. Somewhere between the weaker fast setting araldite, and its slow setting counterpart. Quik Steel is a metal reinforced epoxy putty, with slightly questionable adhesive properties needing care to ensure it has bonded properly, but ideal if a hole has to be bridged, or where the adhesive needs to be moulded to a shape which it will hold while it sets.

The main Manufacturer - Plastic Padding defines their two products Chemical Metal, and Super Steel: Chemical Metal being polyester resin with aluminium particles, and Super Steel being Epoxy resin with alu particles.

So consider if you want to rely on stanchions glued with epoxy, or find a welder! My own view would be that you will not have a large enough glued area for the joint to take the potential shock load safely.

Just happens I have been researching this for an awkward repair!
 
There must be products out there because some cars (Lotus Elise) and and many aircraft are 'glued' together.

However these adhesives may only work well under shear rather than tensile loading?

Don't think the stuff sold to consumers and mentioned earlier is comparable because it won't be.
 
ianj99 said:
There must be products out there because some cars (Lotus Elise) and and many aircraft are 'glued' together.

However these adhesives may only work well under shear rather than tensile loading?

Don't think the stuff sold to consumers and mentioned earlier is comparable because it won't be.
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It's quite commonplace for aluminum and its alloys to be epoxied together, I have a bike made in this manner and some of the Lotus cars were put together.

My son-in-law does a lot of research on wing assembly for EADS and those are bonded with epoxides.

However, there is a world of difference between the assembly conditions for all the above and the proposals from the OP.

The reference to cold-welding could be the process of sintering - applying extreme pressure to a special mix of metal powder to produce complex shapes - it used be quite popular 20 years ago, but advances in CNC techniques have made it redundant.
 
charles_reed said:
It's quite commonplace for aluminum and its alloys to be epoxied together, I have a bike made in this manner and some of the Lotus cars were put together.

My son-in-law does a lot of research on wing assembly for EADS and those are bonded with epoxides.

However, there is a world of difference between the assembly conditions for all the above and the proposals from the OP.
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Epoxies are quite widely used in various applications, but the epoxy and the joint will be carefully engineered to the stresses the joint is to be placed under, and as Charles rightly points out, they wont be using araldite from the local Homebase! Also the preparation of the surfaces to be joined will be strictly controlled to specific standards.

All a world away from to trying to glue something back together with B&Qs best!
 
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