MTFCA Forum

My whole frame viewtopic.php?f=2&t=13134 was nearly all very old corroded bolts. Now after sandblasting and priming I am beginning to rivet which I have never done before. Unfortunately the 1/4 Lang's bucking bar https://www.modeltford.com/item/B-BAR-2.aspx is back ordered. I have the 1/4 rivet jack. See picture I put the correct per Lang's rivet through a hole and it seems like it sticks out very far (yes that is my magnificent weld job of the hairline cracked corner bracket). My understanding is the rivet is supposed to both expand in the hole and mushroom the head so probably that's why it seems long? I would like to cold set these but it seems like sources are saying heat them up. I have an oxy-acetylene torch. Do you heat them up before you put them in the hole or put them in heat and buck? Or just cold do them?

I found this general piece in the archives: http://www.mtfca.com/discus/messages/80 ... 1235094026

I am tempted to buy these air rivet hammers for my cheapo Harbor Freight air hammer tool: https://tinyurl.com/yyryogsf especially since the 1/4 hand bucking bar isn't available.

I got my bar from Jim Dix.
Big Flats Rivet Company
(607) 562-3501

http://bigflatsrivet.com/

Leave the pieces bolted together to keep them aligned and replace the bolts with rivets one at a time. Put the rivet in the hole, back it up, turn it yellow-orange, and mash it with the bar and a BFH. I put the rivet in with the business end out where it's easiest to reach. I recruited another pair of hands for this job. My neighbor held the torch to keep the rivet soft and I did the mashing. If I do this again I want a third person to hold the backup weight against the rivet. I did that with clamps, but it was a pretty clumsy setup.

Not the ideal backup.

If you're replacing the front cross member you can rivet the brackets to it out of the car, then install them in the frame together.

Excellent work Steve. I agree that extra hands make the job much easier. One pair is charged with the heating, I fit and mash, while a third pair holds the back-up bar/jack. Doing as much as you can before fitting an assembly to the frame makes the job easier.

Allan from down under.

I made a real heavy bucking bar in the lathe to back up the rivets in my truck frame. Then I used an air hammer with the correct tip to fit the round end. Heat the rivet and go to it till it is the shape you want. If it cools down heat it again and keep at it. You will get there.

Thats a really nice looking job, Steve.

Ignacio

The comments posted are correct, use heat on that rivet to get it hot, it then expands to fill the hole. Your photo seems to show the holes enlarged for the use of those nuts and bolts, and the new rivet seems to be too small in diameter. The rivet shank must fit the hole securely, not loose.


Use a rivet air gun and the proper tools for setting the head on the plain end of the rivet. Bucking bars can be made from steel pieces depending on the location of the rivet. Big Flats Rivet makes tools, and they make Rivet Jack Screws too for doing bucking inside a 'C' frame rail. Chose to just make some from strong bolts, and they worked good, although single use.

Here's the one-man home garage install method, having a helper on some rivets is nice. Other methods may work better.


Use of bolts as Jack Screws
Results one-man operation, some oversized holes needed larger dia. rivets

I found that 5/16ths bolts were a bit loose in those holes but the metric 8mm bolts fit a bit snugger.That may help keep things aligned better

You can make your own bucking bar from a heavy piece of metal that fits the application. You can make a round half ball shaped hole by using a drill bit of the right diameter and grinding it to the shape that will make a half round hole.
Place the bucking bar piece in the frame to where it will hold the rivet in place with the rivet head in the bucking bar hole. Now find a wedge of some kind. It could be a chisel or what I have used in the past is a wood splitting wedge.
Drive it in place so as to push the bucking bar onto the rivet head. Heat the rivet and round it over how ever you choose with a rivet set of some kind. Knock the wedge out and go on to the next one. This will work on most frame rivets. You might have to use "C" clamps on rivets that are in the flat bottom of the frame that are too far to use a wedge.
It pays to have a lot of "junk " around to get creative with.

Thanks, how or with what do you grind the dome shape?

Herb Iffrig wrote: ↑

Thu Sep 10, 2020 7:38 pm

You can make your own bucking bar from a heavy piece of metal that fits the application. You can make a round half ball shaped hole by using a drill bit of the right diameter and grinding it to the shape that will make a half round hole.
Place the bucking bar piece in the frame to where it will hold the rivet in place with the rivet head in the bucking bar hole. Now find a wedge of some kind. It could be a chisel or what I have used in the past is a wood splitting wedge.
Drive it in place so as to push the bucking bar onto the rivet head. Heat the rivet and round it over how ever you choose with a rivet set of some kind. Knock the wedge out and go on to the next one. This will work on most frame rivets. You might have to use "C" clamps on rivets that are in the flat bottom of the frame that are too far to use a wedge.
It pays to have a lot of "junk " around to get creative with.

Why do Steve Jelf's pictures and videos look so interesting? My guess is semi-retired sign-painter takes his time with composition?

When I was thirteen Mom bought a Kodak Pony for taking slides, and within a couple of months I had taken over as family photographer. I got hold of a Kodak publication called How to Take Good Pictures. It did just that, explaining elements of good composition and pointing out things to avoid. In the subsequent 66 years I've taken plenty of shots that were humdrum or bad, but I think that book has helped me take a lot more good ones than I would have without it.

This shot of me with Stoveoil and Mike was the first picture Mom took with the new Kodak Pony. (Sorry for the drift.)

We started riveting today. It does take 3 people. Three rivets done then we ran out of acetylene.

It is a lot of hammering even when the head is red hot to get one of these done.

Dan's bolts are an excellent tool when riveting inside the frame rails. I drill the head to take the rivet head, and the nuts are used to jam the rivet/bolt in the frame rail. Then there is no need for a bucking bar/tool, as there is no bucking! With these, it is almost a one man job, but I still have someone on the torch doing the heating.

Allan from down under.

So my original Air Hammer retaining spring was too tight for a 1/4 bucking bar. I bent it to fit and now it is too loose, see picture. The bucking bar goes flying. Should I try to bend it again to fit better or does anyone sell them to the right size? I looked but didn't find one. I have 2 original retaining springs and they both are the same size. They start out too tight for a 1/4 bucking bar.

I recently posted on this subject, apologies to those that have seen this already but I remain concerned that people sometimes don't realise it's important to heat the entire rivet, not just the head:

An important point to note when you're doing the job (and really the main reason for riveting rather than bolting):

The entire rivet should be heated, ideally in a forge, before putting in place and hammering. If you can't do this then at least the entire shaft should be heated by whatever mechanism you choose.

This is because it's important for the rivet to expand radially to properly fill the hole it's placed in, as well as compress longitudinally. This allows proper lateral fixing of the chassis members - and thus minimisation of movement between members - in addition to the simple clamping of one member to another.

To be clear, if you just heat the end of the rivet in place, then hammer, you will be unlikely to achieve the best fixing you could and would in fact be better off bolting the members together as bolting will give a better clamping force (albeit to the detriment of aesthetics). This is because in heating just the rivet end and hammering all you're really doing is forming a head with the soft metal, and not compressing/deforming the relatively harder shaft against the receptacle it's fitted into.

In fact I suggest that (if you've a strong enough air hammer and buck) cold hammering throughout the operation would probably be better than heating just the rivet end.

To illustrate what I describe here's a couple of video clips that show how to go about it:

https://www.youtube.com/watch?v=Sn1m1egXY5I
https://www.youtube.com/watch?v=bWmFxtGw_Lo

Also, at about 1:30 on this video, you can see a good example of what I was getting at about how the rivet should expand against the material it's fixing:

https://www.youtube.com/watch?v=o526BPSxJc4

One other thing; if the buck isn't the right size you can re-form it, or create a new one simply by heating the end and hammering it over a rivet head or suitably sized ball bearing, then quenching in oil to harden it. My recollection of T chassis rivets is that some of them are 5/16" (?) and, at least in NZ, it was impossible to get the correct buck size, so I made a completely new tool for this. I also made the rivets since they were unobtainable as well, but that's another story...

Luke, thank you for the interesting videos. In principle I agree to heat the whole thing but are relatively small compared to the large rivets in the video, they cool off fast and setting one up in the frame C with a rivet jack takes far too long for it to stay hot that way. On the other hand I am getting them orange hot and the rest of the rivets gets red hot so I hope we are ok. I am going to retry getting my air hammer to work. It launches the bucking bar right now because of the retraining spring issue which would be entertaining under other circumstances.

What worries me is your description of the riveting tool going "other places." The spring is only there to keep the tool in the hammer while it is not in use. Do NOT press the trigger until the tool is firmly on the end of the rivet and being held tightly. Then you push the trigger, and it should hammer against the rivet--not go flying about the area. The advantage of the air hammer is the rapidity of the blows, allowing a lot of expansion in a short length of time--while the rivet is hot. The bucking bar has to be held solidly to provide the backing for the riveting tool to work against.

Okay I think I have this. The key was per suggestion you put the air hammer on the rivet so it won't eject the bucking bar. I also focused the torch on the shaft that is showing not the head to get it good and hot. The running board hangers are half on now with the top rivets in. Looks pretty good I think in picture 2. It is much faster with an air hammer bucking bar.

That looks great
Good job
I am getting ready to do some riveting on mine soon

Thanks. I have found the air hammer is superior to a hand bucking bar for both speed and result. Also don't let your teenager play with the oxy-acetylene rig they will use up all the gas and ask you to get the bottles filled twice before you forbid them from touching it. I count approximately 34 rivets on a frame so using the air hammer speeds it up quite a bit. More results pictured.

dmdeaton wrote: ↑

Thu Nov 26, 2020 9:14 pm

That looks great
Good job
I am getting ready to do some riveting on mine soon

Uh-oh rivet jack is too big for the front.

If you are going to use the stock starter push switch mounting location I hope you didn't rivet the top strap to the frame. It looks like it got riveted in your picture but I can't tell for sure. The switch mounts with one hole going under the brace strap on the driver's side (USA) front running board bracket and takes a bolt and castle nut.
The frame has a hole drilled for the other mounting hole of the two in the switch. You can mount the switch someplace more convenient for your speedster's use if need be.

Good eye yes it is riveted. I can cut it off if necessary.

kmatt2 wrote: ↑

Sat Nov 28, 2020 2:05 pm

If you are going to use the stock starter push switch mounting location I hope you didn't rivet the top strap to the frame. It looks like it got riveted in your picture but I can't tell for sure. The switch mounts with one hole going under the brace strap on the driver's side (USA) front running board bracket and takes a bolt and castle nut.
The frame has a hole drilled for the other mounting hole of the two in the switch. You can mount the switch someplace more convenient for your speedster's use if need be.

ivaldes1 wrote: ↑

Sat Nov 28, 2020 12:00 pm

Uh-oh rivet jack is too big for the front.

I just sized mine up also and will snag a couple threaded couplings so I can cut them down. I assume you are doing the same? Did you cut the rivet length?

I did not cut any of the rivets because they are supposed to expand into the hole when heated and driven. They form a nice dome when done correctly even if it sticks up a lot at first. I purchased bolts and nuts in various sizes for the spots that my jack is too big for.

Flip the frame over if you can. It is much easier to do nearly all the rivets with the frame upside down. Working up and under with a hot torch and bucking bar is much more difficult than working down.

Harvard riveters are the best.

Ignacio, why didn't you just cut off the extra length on the coupling nut so it would fit? Just curious. Dave

I had not thought of that. Also if I understand your meaning, that would mean a one-way modification to the rivet jack with no going back. The shorter bolts seem to work ok so I didn't think about just cutting it. Another idea that I just thought of is to unscrew the bolt in the jack and see if just a regular sized nut instead of the wide 'nut' on the jack would work.

D Stroud wrote: ↑

Wed Dec 02, 2020 5:59 am

Ignacio, why didn't you just cut off the extra length on the coupling nut so it would fit? Just curious. Dave

I will post some pics tomorrow as I am doing my front crossmember. Hope they turn out as nice as yours did

It has been suggested to me to heat the shaft instead of the head to make the rivet expand to fill the hole but I've noticed that this makes the rivet head skew to the side because I am not perfect at making the tool go straight on. Also my $15 (not a typo) Harbor Freight medium air hammer isn't working right. It is only vibrating about every 4th pull of the trigger and often not at all. I see from reviews that this occurs often enough to other people. I am going to get another hopefully better one.

Ignacio, have you tried lubing your air hammer? Might be worth a shot. Just a thought. Dave

Lubed, has been lubed all along, no change. It didn't work very well out of the box.

D Stroud wrote: ↑

Thu Dec 10, 2020 2:29 am

Ignacio, have you tried lubing your air hammer? Might be worth a shot. Just a thought. Dave

I had the same problem today with the rivet bending over. I called the rivet man and he told me to not use the domed air chisel until last. Heat red hot then wail with a good hammer like driving a nail. This will squeeze the rivet out and tighten it up. Heat up again. Then use the dome only to dress the head. It worked good for me earlier. I am going to finish mine Saturday

I picked up this one from Northern Tool for $49.95. It looks superior in every way. It has a quick change chuck, comes with 3 end tools and actually works every time.

So I was almost out of oxy-acetylene so I setup four to do all at once. A problem has been that they have a tendency to lay over somewhat off center. Is that okay?