The Ford Barn

keeeef · 03-02-2014, 10:11 AM

Just wondering why crossmembers were riveted and not bolted in. Just bought a used rear crossmember for my 36 pickup and don't have much experience of rivetting.

Kube · 03-02-2014, 10:32 AM

Rivets are much stronger than bolts and of course have much less tendency to loosen when the frame flexes.

rotorwrench · 03-02-2014, 11:37 AM

Just to add, rivets expand when squeezed or bucked and fit the bore of the drilled hole much more securely than a bolt. Many steel bridges and buildings that were constructed with rivets over a century ago are still standing and in use today.

In aviation, pins and bolts are utilized more now than ever before but the bore of the drilled hole is reamed to fit the pin or bolt tightly and small increment oversizes are available to repair these if they become loose in service.

Hanson Rivet has all sorts of replacement rivets and they can be heated with a torch to make bucking the rivet easier but they aren't easy for the larger sizes and special equipment has to be either purchased or fabricated to aid in bucking or squeezing them. It helps if you have like minded friends who can get together and do multiple jobs at one time so as to have the help it takes to move and position frames and such for best access & grip on the big pneumatic air hammers and bucking bars.

ford38v8 · 03-02-2014, 01:28 PM

Big Flats Rivet Co www.bigflatsrivet.com
Authentic rivets for vintage cars

john in illinois · 03-02-2014, 01:41 PM

I learned a great way to heat rivets helping a friend put in a crossmember.

Put the rivet in the hole cold and position bucking bar. get a stick welder cutting electrode-ours were from harbor freight. Turn the welder up to about 180amps-may vary. Touch the electrode to rivet end and the entire rivet heats completely through. Cherry to white hot. Then hit it with the air gun.

A lot simpler than using a torch and sure expansion in the hole.

John

PeteVS · 03-02-2014, 01:53 PM

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Quote:

Originally Posted by john in illinois

I learned a great way to heat rivets helping a friend put in a crossmember.
Put the rivet in the hole cold and position bucking bar. get a stick welder cutting electrode-ours were from harbor freight. Turn the welder up to about 180amps-may vary. Touch the electrode to rivet end and the entire rivet heats completely through. Cherry to white hot. Then hit it with the air gun.
A lot simpler than using a torch and sure expansion in the hole.
John

OK, so you're saying to put the rod onto the end of the rivet and hold it there without creating an arc? How long should it take to heat up a 1/4" rivet?

ford38v8 · 03-02-2014, 02:09 PM

Blink three times.

PeteVS · 03-02-2014, 08:10 PM

Has anyone used this method for shrinking sheet metal?

Torchie · 03-02-2014, 08:55 PM

Quote:

Originally Posted by PeteVS

Has anyone used this method for shrinking sheet metal?

I have heard of people doing some thing like this. Would have to be cautious not to burn thru the sheet metal I would think.
Also have heard of people using a MIG welder with the gas shut off to create a hot spot as well. I can't claim to have done it myself.
Torchie.

Ed Pitts · 03-02-2014, 09:09 PM

A gas torch and a wet rag will work on shrinking metal. Ed

dumb person · 03-03-2014, 03:58 AM

Tell me more about this arc welder method plz

Quote:

Originally Posted by PeteVS

Has anyone used this method for shrinking sheet metal?

i have used an arc welder to shrink sheet metal but it is not preferable to heating with gas.

john in illinois · 03-03-2014, 08:26 AM

Pete when you use a cutting rod made for cutting steel with an arc it does not deposit any metal. You arc to the rivet and it is instantly hot. Then you drive it.
John

Bruce/CT · 03-03-2014, 12:55 PM

John,

Thanks for the great tip. I have Rivets and Riveting Air tool from Big Flats but couldn't figure out how I was going to heat the Rivets. What stick welder do you recommend? I have a MIG & TIG but no stick and have to do some riveting soon.
Thanks,
Bruce/CT

JWL · 03-03-2014, 01:04 PM

Rivets are NOT stronger than bolts. However, properly installed rivets can be crushed tightly into non-precision holes which tends to reduce movement or "working" at the joint. A very desirable circumstance for a crossmember attachment.

Mart · 03-03-2014, 01:12 PM

Keef, You don't HAVE to rivet the crossmember in. As your truck is somewhat non-stock you could bolt it in and back the bolts up with some strategically placed welds. Or just weld it in completely.

Mart.

keeeef · 03-03-2014, 02:55 PM

Thanks guys for all the suggestions. I had a couple of small cracks in the crossmember and lots of help in a previous thread. I ended up drilling small holes to stop them spliiting further, deep v'd the cracks and welded them up with the recommended 'soft' mig wire. Then wandering round a swapmeet here in the UK yesterday I found a perfect '36 crossmember for sale at £10!!

I only have a mig so no way of heating up rivets unless I get help. Might try Mart's suggestion of bolting and welding as it's not a restoration project more of a get it on the road and use it truck or may run it this year with the repaired crossmember and keep a close eye on it.

Thanks again, always get great advice on the Barn

36tbird · 03-03-2014, 05:42 PM

You can use some button head bolts to simulate rivets, at least on one side.

Fe26 · 03-03-2014, 07:20 PM

Quote:

Originally Posted by JWL

Rivets are NOT stronger than bolts. However, properly installed rivets can be crushed tightly into non-precision holes which tends to reduce movement or "working" at the joint. A very desirable circumstance for a crossmember attachment.

True. Another way of looking at this is, rivets are made from Low Carbon (soft) steel. Rivets are designed and strategically placed to allow the riveted members to flex. Their used to be a field of Heavy Engineering that dealt with rivets, their size, application, layout and spacing, sadly all that knowledge is gone now.

Binx · 03-03-2014, 07:55 PM

Quote:

Originally Posted by keeeef

Thanks guys for all the suggestions. I had a couple of small cracks in the crossmember and lots of help in a previous thread. I ended up drilling small holes to stop them spliiting further, deep v'd the cracks and welded them up with the recommended 'soft' mig wire. Then wandering round a swapmeet here in the UK yesterday I found a perfect '36 crossmember for sale at £10!!

I only have a mig so no way of heating up rivets unless I get help. Might try Mart's suggestion of bolting and welding as it's not a restoration project more of a get it on the road and use it truck or may run it this year with the repaired crossmember and keep a close eye on it.

Thanks again, always get great advice on the Barn

You'll be okay if it is for road use and not uneven terrain. Remember, for every rivet removed and a bolt installed, the missing shear strength of the compressed connection will transmit through some of the frame's rivets so keep it on paved roads and you'll be fine.

Lonnie

rotorwrench · 03-04-2014, 12:14 PM

One thing a person should keep in mind is that a bucking a hot steel rivet in effect is a forging process that closes the metals bond structure up a bit during the process. I would venture that they are not much softer than a grade 5 type bolt since both can be easily drilled with a high speed steel drill bit. They put enough of them in the frame gusset locations and for braces to strengthen the joints pretty well. You can use bolts, but bolts will loosen in service unless they fit the hole very tightly and even then, they should be periodically retorqued. Those old frames flex a lot more than modern ones.

03-02-2014, 10:11 AM	#1
keeeef Member Join Date: Mar 2013 Location: London, UK Posts: 93	Crossmember Rivets Just wondering why crossmembers were riveted and not bolted in. Just bought a used rear crossmember for my 36 pickup and don't have much experience of rivetting.

03-02-2014, 10:32 AM	#2
Kube Super Moderator Join Date: May 2010 Location: Wisconsin, USA Posts: 10,539	Re: Crossmember Rivets Rivets are much stronger than bolts and of course have much less tendency to loosen when the frame flexes. __________________ "I can explain it for you. However, I can't understand it for you".

03-02-2014, 11:37 AM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: Crossmember Rivets Just to add, rivets expand when squeezed or bucked and fit the bore of the drilled hole much more securely than a bolt. Many steel bridges and buildings that were constructed with rivets over a century ago are still standing and in use today. In aviation, pins and bolts are utilized more now than ever before but the bore of the drilled hole is reamed to fit the pin or bolt tightly and small increment oversizes are available to repair these if they become loose in service. Hanson Rivet has all sorts of replacement rivets and they can be heated with a torch to make bucking the rivet easier but they aren't easy for the larger sizes and special equipment has to be either purchased or fabricated to aid in bucking or squeezing them. It helps if you have like minded friends who can get together and do multiple jobs at one time so as to have the help it takes to move and position frames and such for best access & grip on the big pneumatic air hammers and bucking bars. Last edited by rotorwrench; 03-02-2014 at 11:44 AM.

03-02-2014, 01:28 PM	#4
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 7,634	Re: Crossmember Rivets Big Flats Rivet Co www.bigflatsrivet.com Authentic rivets for vintage cars __________________ Alan

03-02-2014, 01:41 PM	#5
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,249	Re: Crossmember Rivets I learned a great way to heat rivets helping a friend put in a crossmember. Put the rivet in the hole cold and position bucking bar. get a stick welder cutting electrode-ours were from harbor freight. Turn the welder up to about 180amps-may vary. Touch the electrode to rivet end and the entire rivet heats completely through. Cherry to white hot. Then hit it with the air gun. A lot simpler than using a torch and sure expansion in the hole. John

03-02-2014, 02:09 PM	#7
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 7,634	Re: Crossmember Rivets Blink three times. __________________ Alan

03-02-2014, 08:10 PM	#8
PeteVS Senior Member Join Date: May 2010 Location: FP, NJ Posts: 2,828	Re: Crossmember Rivets Has anyone used this method for shrinking sheet metal? __________________ Don't never get rid of nuthin!

03-02-2014, 09:09 PM	#10
Ed Pitts Senior Member Join Date: May 2010 Location: Irving, Texas Posts: 598	Re: Crossmember Rivets A gas torch and a wet rag will work on shrinking metal. Ed

03-03-2014, 08:26 AM	#12
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,249	Re: Crossmember Rivets Pete when you use a cutting rod made for cutting steel with an arc it does not deposit any metal. You arc to the rivet and it is instantly hot. Then you drive it. John

03-03-2014, 12:55 PM	#13
Bruce/CT Senior Member Join Date: May 2010 Location: Middlebury, CT Posts: 782	Re: Crossmember Rivets John, Thanks for the great tip. I have Rivets and Riveting Air tool from Big Flats but couldn't figure out how I was going to heat the Rivets. What stick welder do you recommend? I have a MIG & TIG but no stick and have to do some riveting soon. Thanks, Bruce/CT __________________ Failure is simply the opportunity to begin again, this time more intelligently.......Henry Ford

03-03-2014, 01:04 PM	#14
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: Crossmember Rivets Rivets are NOT stronger than bolts. However, properly installed rivets can be crushed tightly into non-precision holes which tends to reduce movement or "working" at the joint. A very desirable circumstance for a crossmember attachment.

03-03-2014, 01:12 PM	#15
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 9,239	Re: Crossmember Rivets Keef, You don't HAVE to rivet the crossmember in. As your truck is somewhat non-stock you could bolt it in and back the bolts up with some strategically placed welds. Or just weld it in completely. Mart.

03-03-2014, 02:55 PM	#16
keeeef Member Join Date: Mar 2013 Location: London, UK Posts: 93	Re: Crossmember Rivets Thanks guys for all the suggestions. I had a couple of small cracks in the crossmember and lots of help in a previous thread. I ended up drilling small holes to stop them spliiting further, deep v'd the cracks and welded them up with the recommended 'soft' mig wire. Then wandering round a swapmeet here in the UK yesterday I found a perfect '36 crossmember for sale at £10!! I only have a mig so no way of heating up rivets unless I get help. Might try Mart's suggestion of bolting and welding as it's not a restoration project more of a get it on the road and use it truck or may run it this year with the repaired crossmember and keep a close eye on it. Thanks again, always get great advice on the Barn

03-03-2014, 05:42 PM	#17
36tbird Senior Member Join Date: May 2010 Location: nw SanAntonio, TX Posts: 940	Re: Crossmember Rivets You can use some button head bolts to simulate rivets, at least on one side.

03-04-2014, 12:14 PM	#20
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: Crossmember Rivets One thing a person should keep in mind is that a bucking a hot steel rivet in effect is a forging process that closes the metals bond structure up a bit during the process. I would venture that they are not much softer than a grade 5 type bolt since both can be easily drilled with a high speed steel drill bit. They put enough of them in the frame gusset locations and for braces to strengthen the joints pretty well. You can use bolts, but bolts will loosen in service unless they fit the hole very tightly and even then, they should be periodically retorqued. Those old frames flex a lot more than modern ones.