Gluing Aluminium

When bonding rubber to metal it's usually sand blasted and cleaned with MEK. A firm I worked for had an order from a local food manufacturer for stamps to seal the cellophane tops on to ready meals, which were to be made from Silicone and Aluminium. Bonding rubber to steel is no issue although we hadn't tackled Aluminium before, so I got on to our supplier for Silicone and asked about adhesives and compounds for bonding. They suggested bonding the Silicone on as quickly as possible after blasting and cleaning, as in within 30 mins, otherwise the forming oxide layer would prevent the adhesive from gripping.

I did a load of testing work on some samples, wrote the spec for the job, explained it all to the production engineer and his two operatives that were doing it, watched them do the first one and left it at that. A few weeks later the stamps came back as they were delaminating before being used, and after an investigation it turned out they had left the blasted Aluminium plates sat around for two days before bonding as they had other more important jobs to get through.

MEK and Aceton used for the final cleaning step should be pure so that there is no residue left behind after evaporation. I mentioned Fokker for their bonding of aluminium for their fuselages. If I remember me well they applied anodising with open pores prior to bonding. And then again they had to be very careful to remove all anodising liquid to exclude corrosion afterwards during lifetime.

OK, first feedback on JB Weld Original Cold Weld Glue.

Its easy to use, degrease & clean the aluminium well then rough it up. Mix the epoxy and apply. Its quite slow curing so take your time and be careful not to overspread it. I put a thin layer on each piece and clamped them in place.

It takes a few hours to harden enough to to unclamp and 24 hours to fully cure.

Once cured, its good and strong.

Stuart

I watched a very old documentary last week covering the original concept,design and production of our first

commercial jet airliner, the Comet.

The de Havilland designer was a Mr Bishop , his original concept was for the 'window frames' to be glued

in place.

During the build Mr Povey, the Production Manager 'persuaded' him to change his glue idea to one of conventional riveting.

The rest is history.

Stuart, I have only just seen your thread otherwise would have commented earlier.

Looks like you have now found the extremly useful attributes of JBW. There are other alternatives equally as good of course but are usually much more expensive which is a factor to be considered if it is going to sit on a shelf between occasional useage.

As Tim and I'm sure like some others on here I have built and raced IOM and Mablehead yachts but not recently. Stangely enough I don't recall having a use for JB on any of them though.

Hope your model sails well

Ramon (Tug)

When I made an engine mount for a OS Wankel rotary engine, I glued all of the frame with Purbond Al glue. It was a 2 part, with a brown activator on one surface, and a opaque looking glue to the other part. The pieces were glued end on. The instructions back in 1985 was to lightly sand then apply the activator as soon as possible after sanding. Then sand the other areas where the opaque gel goes, again apply the gel as soon as sanded. Then assemble within 60 seconds, and hold in place for a few hours until cured. I also made a curtain rail extension which lasted until the sale of the house in 1997. So lasted at least 12 years. The engine mount never failed in the life of the model.

Neil

I have found that the slow curing Araldite is stronger than the quick type.

To conclude.

My JB Weld 'original cold weld' has now set and is frankly fantastic. My one observation is to be neat in applying it, once dry the only way to remove it from surfaces seems to be mechanical, filing it off.

Ramon & Tim, I sometimes dream of a Marblehead - they are so graceful on the water. For a quick dip I have a 'Tupperware' DF65 which is fun to sail but about as beautiful as a brick. But to be honest, its the building of the boat, and designing the mechanics/electronics that I enjoy most so 'near scale' is likely to remain my preferance.

Perhaps a steam powered boat....

Stuart

Hi,

Just thought I'd report back after completing all my aluminium gluing.

JB Weld is fantastic stuff as long as you prepare the aluminium carefully. But you do need to take care on being neat when applying the mixed glue, it dried hard and sanding it off can impair the aluminium surface, I found that after an hour the glue was firm but not hard and excess could be removed with a hobby knife. This will leave a stain which, once fully hardened, can be removed easily with 1000 grit paper.

I am painting the aluminium for corrosion protection; after an etching primer the aluminium and any visible glue takes the paint well with no remaining sign of the glue in the joint.

Regards

Stuart

I don't think David Lammas' excellent little book Adhesives and Sealants (WPS21) has been mentioned (currently in the smallest room here).

Just found it on Amazon, £6.25 so worth a punt.

Thanks for the hint

Stuart