Hello,

We are looking at doing some hot rivetting on the steel end framing of a 1912 wood coach. What are those folks who are doing hot rivetting using to heat the rivets? Looks like some are using a rosebud tip on a torch, kerosene oven, induction heating, etc.

Thanks,

Richard

At IRM, I've seen a diesel burning "rivet furnace" used, probably very similar to what you referred to as a "kerosene oven".
3 important facts to remember;
1.) Rivets expand when heated, so, a rivet that fits tightly in its intended hole when cool will probably NOT fit when red hot.
2.) The hotter the rivet is, the more time you will have available to work the metal.
3.) The hotter the rivet is when the head is formed, the tighter the joint will be, after the rivet cools.

Jeff

I prefer a propane forge for rivet heating. Much easier to control heat, as you can "burn" a rivet easily with an acetylene torch:

http://www.forgemaster.com/shop.php?category=9

An inexpensive and fast method for doing this type of work is to build a small forge out of firebrick or the like and use a large propane burner for heat. This is not the ideal set up but does a couple valuable things for the riveting team. First, you want to be sure the rivet has had enough time to "soak" in the heat so that the rivet is uniformly heated throughout. Second, it is easier to control the heat so that one side is not melting and the other side is still black. It is very easy to burn a rivet so that the end result is less visually appealing (ie pitted and rough), and the strength of the rivet is decreased due to decarburization. A nice yellow color will yield a ductile and strong rivet, overheating is not beneficial. Also, be sure that your snap is clean to prevent marring the head. Best of luck and enjoy the process, hot riveting is a lot of fun!

Best,

Stathi

We've done a lot of hot riveting at Pennsylvania Trolley Museum, including some pretty big ones in car frames, etc. We use a "rosebud" heating tip on an otherwise stock oxyacetylene (or in our case, oxygen/MAPP) torch. The rivets are heated in a small piece of steel channel to concentrate the heat. This method sets up quickly and can be quickly turned off when not needed. The torch operator needs to be a little careful to avoid getting any part of the rivet to melting temperature, but this process has proven successful for many thousands of rivets.

Why does this work, I know it must work as people have been doing it for years but like Jeff said "Rivets expand when heated, so, a rivet that fits tightly in its intended hole when cool will probably NOT fit when red hot." I thought cooling a rivet would work better so it would expand snugly in it's hole.

RCD, why does it work? Because you're heating the rivet to a temperature it becomes plastic, like modeling clay. Drop a hot rivet and it'll bend.

You're going to be hammering on the end. What does that do to a cylinder? Right - the cylinder gets shorter, and also fatter.

As it gets fatter, it extrudes to fill the hole completely, even if the hole is rough cut.

So it doesn't actually hurt for the rivet to be undersize. Not undersize is bad. If the rivet doesn't go in freely, how do you get it in?

As stated by a couple of other posts in this thread the use of a small forge built with fire brick and heated with a propane burner will do a good job of getting your rivets hot and keeping them that way. It is important that they are heated to at least a yellow heat but not so hot that they are sparking. If they are doing that then they have been overheated and are burning. The fit between the rivet and the hole should be smooth and not to tight. The rivet will expand when heated and will swell in the hole when you dirve it with a air hammer. You need to buck the head and drive the shank. 1/2" to 3/4" dia. rivets will need at least a 90lb hammer to get the job done.

Good luck and make sure you use good hearing protection.

http://naugy.blogspot.com/2009_07_01_archive.html

Our version of the hot rivet action. The "forge" is a bit crude, but effective.

Howard P.
Buck-em, CT

I was look at the Railtown 1897 State Historic Park
http://railtown1897.wordpress.com/2009/ ... rivetting/
w/o the picture of the how-to.

Stan