rivets

I am making a 6 " diameter stainless chimney for a boat, and want to close rivet it with some chunky rivets, what's the biggest you can hand rivet cold ?

Copper would be ok, but I don't know if it would corrode in contact with stainless ? One I made with a cast steel eye bolt on it corroded around the bolt in no time.

I might go for hot rivets if necessary. I shall be making up a jig from steel beam that fits inside the tube, to back up the riveting.

1/4" is about as big as you want to go cold with a 4lbs club hammer, 3/16" may be easier if you can't get a really firm support under the rivit.

On these size rivits it does not really work to heat the rivit, place it and then form the head as there is not enough metal in teh rivit to hold the heat, it will have cooled by the time you have the hammer in your hand. If you have access to oxy then get a helper to heat the end when the rivit is in place and then form the head.

Threaded rivits are another option, just fit nuts inside and have the factory formed head on the outside

You can lock the threaded rivits by peining the end protruding from the nut. Ian S C

Hi Richard

This link may help re corrosion **LINK**

Regards
John

Copper and stainless steel are widely used together in the marine industry both above and below the waterline. Many rudder fittings are riveted with copper rods belled over. Above the waterline it is common practice to put an eye in a stainless steel wire or wire rope up to around 6mm diameter. The eye is made around a stainless steel thimble and the tails are crimped together using a talurit which is basically a thick walled copper tube swaged onto the wire with a special tool. Provided the copper is well annealed to start with, you can get a considerable upset. Best to use a fewer number of heavy strokes rather than lots of soft ones as copper work hardens rapidly.

On a 6" chimney I would have though 1/4" is as large as you want to keep nice proportions. Go for it!

When i was an apprentice we use a rivet that could be driven into a slightly smaller blind hole. They were slightly fluted in a spiral. We used them to clip copper wire clips to cast iron.

Does anyone know where or even if they still exist?

Brian

Ps my curser still jumps up the page when i press return. Most annoying.

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Deninitely yes, Brian

... and fairly widely available.

MichaelG.

Thanks mr G. I really do need to make more use of google!

Brian

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I just hit lucky ... recalled them being known as HammerDrive [or some such]

... My Dad worked for GKN, and I think that may have been their trade name.

MichaelG.

Just for the record ... Type U is illustrated here.

MichaelG.