View Single Post
  #252  
Old 22-03-09, 05:14
aj.lec's Avatar
aj.lec aj.lec is offline
Andrew
 
Join Date: Apr 2007
Location: N.S.W AUSTRALIA
Posts: 1,623
Default

The majority of the rivets i used were pre formed with a tapered head
The first one tony showed would have been better but i took the ones i could find
I made the longer 1/2 inch ones as i could not buy them
I used a block of cast (old tractor weight)drilled to the right depth and cut the rod to the depth plus about the diameter of the rod ,heat head only and peaned and mandrelled head to shape

I made up several different length backing bars with the head machined to take the shape of the rivet head
very important to have a tight ,solid backer when driving and forming the opposite head as any movement at all will result in a loose rivet caused by the flexing on the opposing side

I made up a forming bar using a jackhammer tip and machined the curve to suit the size rivet head you want to form.These have good hardened steel on the impact end

I found you get it into postion and wedge in solidly .
Then cut the rivet to length ,About 1/2 inch for 1/2 inch rivets and generally 1/2 inch for the 3/8 rivets as they seemed to need more to fill the voids on the initial strikes
Then begin heating the entire rivet as much as possible .Very important on the first hits as it allows the whole shank to swell into the cavities when driven
The first series of hits i drove directly on to the end until it filled the hole gaps might take several heating turns

Once this was done reheat and i formed a rough head with the ball pein of the hammer trying to get as uniform as possible . This cut down a lot of time doing the actual head forming cycles

Reheat then using the forming bar strike directly then slight circular motions to form a uniform curved head .This may take several reheatings till you get a uniform head pattern and a nice ,tight flat face against the metalwork you are trying to rivet together

I also made up a set of large clamping backing pliers to hold the rivets where I couldnt get a backing bar wedged in to
Even this needed some additional wedging to stop the strike vibration loosening the rivet head

Rest day today as the wrists ,elbows and eyes copped a smashing yesterday
Attached Thumbnails
IMGP2260.jpg   IMGP2261.jpg   IMGP2262.jpg   IMGP2263.jpg   IMGP2265.jpg  

__________________
Have a good one
Andrew

Custodian of the "Rare and Rusty"

Last edited by aj.lec; 22-03-09 at 05:29.
Reply With Quote