riveting new front cross member

[Al 29Tudor]

Good morning Barners,

When riveting in a new cross member in place, is it better to preheat the rivets away from the work or heat them in place?

Thanks for your help.
Al

[RonC]

Away from work

[Al 29Tudor]

Thanks RonC

[BRENT in 10-uh-C]

Depends, most people do not have the ability nor the proper tools, so that factors in too. If you preheat away from the crossmember and try to insert it, do you have the capability to move the molten rivet quickly enough to get it installed and firmly seated to be bucked? If not for certain, then you will likely have a botched job that is not strong. On the flip side, if you heat the rivet in-place but use too large of a flame, generally the exterior gets hot along with the two prices being riveted however the shank does not become heated so you do not see any swelling of the rivet shank. Also, most people do not have a rivet gun and find the rivet does not truly get compressed. On a front crossmember rivet, 'one really needs a 3X pneumatic rivet gun and a large (mass) bucking anvil. My suggestion is obtain the correct tools and practice on a few items first, and you will likely master it quickly.

[H. L. Chauvin]

Hi Al,

Found it most convenient to:

1. Install all rivets cold with round head pointing downwards; &,

2. Securely support the bottom round head of rivets in the recess of a homemade bucking bar(s) resting on a solid concrete floor; &,

3. With a very fine flame of an acetylene torch, heat just the very top of the end of the exposed rivet shank; &,

4. When cherry red, set torch down on a homemade torch holder & form & tighten the rivet with a hand held rivet tool, (sold by Model A vendors), & hit with several licks of a medium sized hammer as opposed to a few licks with a large maul.

Note:

A. If the rivet holes in any of the parts of the steel frame are too large, they need to be welded solid & re-drilled for a tight fit because a rivet will "not" tighten properly in too large a hole.

B. Two (2) homemade bucking bars can be made from 3/16" thick x 1" x 1" steel angles:

(1) One shaped like a figure "6", about 7" high, but with 90 degree corners as opposed to a rounded figure "6", & with the bottom of the figure 6 resting on a concrete floor; &,

(2) The other one shaped similar to the letter "Y", securely welded to one end of a length of 2" pipe; & with other end of pipe, (with a pipe cap), resting on a concrete floor. This second bucking bar can be used to securely provide rivets in running board brackets with the tip of the brackets pointing downwards towards the concrete floor.

(3) Tops of both bucking bars can be provided with a 1-1/2" length of a welded 5/8" square steel bar with a rivet round head hole counter sunken in the top side of the square bar with a large drill bit & shaped with a Dremel grinding tool.

Just another simple Model A past experience -- successfully re-did an entire Model A chassis frame with a chain hoist, two (2) homemade bucking bars, & without a helper.

[Al 29Tudor]

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Thank you Brent and H.L.
We have a lot to think about with all the info you have given us.
Neither of us have ever riveted so we are playing catch-up.
Thanks,
Al

[Marco Tahtaras]

Originally Posted by H. L. Chauvin

Hi Al,

Note:

A. If the rivet holes in any of the parts of the steel frame are too large, they need to be welded solid & re-drilled for a tight fit because a rivet will "not" tighten properly in too large a hole.

This is where Brent's comments come into play. If you don't have the correct equipment you have to make adjustments to achieve decent results. Frames made after about June 1928 had the rivet holes punched about .055" +/- (almost 1/16") larger than the rivet so the holes did not require perfect alignment to slip the hot rivet into. Any offset as most holes had was simply filled completely with the hot rivet. Obviously any rivet not entirely heated will simply form a clamp which will work loose over time. Of course most cars are never driven enough to notice any negative side effects other than possibly rust powder coming out around a rivet head.

A search for "riveting" would have revealed a couple past threads that include the post below which actually originated about 15 years ago.


http://www.fordbarn.com/forum/showpo...21&postcount=5

[H. L. Chauvin]

Hi Al,

Another tip is:

1. If one or more rivet holes are too large, weld them up first & grind welds smooth on both sides; &,

2. Fit metal pieces together with same size bolts through the other proper sized holes; &,

3. Then drill through welded-up holes to maintain frame alignment.

4. Once you get started & practice on a few, if I had to guess, riveting Model A frames is all about equally as difficult as your great-grandmother successfully making biscuits from scratch in a wood fired oven with no electronic temperature control.

Get busy! LOL

[Brentwood Bob]

A good method is to bolt the cross member in place and use a couple of helpers. I kept the frame on its side and did fine. the tops of the rivets seen from an overhead view down onto the horizontal frame, as it sits on the drive train, will show the heads of the rivets on the top side of the frame, to be flush with the frame. if you have any mis-alignments of holes at the fitup stage, I would consider drilling them to help with the riveting. Drift punches help with the fitup.and yes, the bolts should be tight until they are removed one at a time to replace with a rivet. try alternating rivets to also keep the alignment.
Remember bob's rule. if you use OEM parts things usually fit and if you use the wrong parts nothing will fit.
Bob

[Al 29Tudor]

Marco, H.L. and Bob,
Sounds like you gents have done this before.
The diameter is on of the questions we had and Marco answered that - .055 oversize and the alignment tips sound right on. align it, bolt it, and remove one bolt at a time and replace it with a rivet. Bob, flush on top you say - so those need countersunk holes.
Thank you all again.
Al

[MichaelSchwarzer]

Hi Al,

we did it the following way: As you say replace rivets with bolts and set one rivet at a time. We heated the rivet in a mobile force, than put it quickly into the frame and securely supported the bottom round head of rivets in the recess of a homemade bucking bar resting on a solid concrete floor. For that reason we hang up the frame on the balcony to make handling easier. Then we formed the rivet with a hand held tool and a hammer. See pictures at http://www.fordmodela.com/restoration/frame/frame/

[Al 29Tudor]

Michael,
Thank you for all the picture of your project. What a nice job you did.
It looks perfect.
Al

[Brentwood Bob]

you will find the holes are countersunk in the cross member if I remember right. Bob

[MichaelSchwarzer]

Yes, holes are countersunk. See pictures. We used oversize rivets for the front cross members.
Al, thanks for your kind words!

Michael

[Brentwood Bob]

great job. Bob