Rivet Locked Passthroughs

Today I’m pretty consistent about making project notes and taking images to jog my memory but this is an example from 14 years ago before I was doing the notes.

I wanted a place in the studio to hang up coats and jackets and hats.  I think I had seen a similar design which also incorporated an umbrella stand.  Also, I wanted to test this type of riveted passthrough which gives the stand its rigidity.

I took an image of the chalk sketch on the floor, and a tool I used to check the rivet alignment but that is all I recorded of the project.  The completed image was done by my professional photographer.

I think I may have started a pilot drill hole on one side of the passthrough and used the tool to insure the drill hole exited the opposite face well centered. The the tool assisted placing the rivet and assuring it would slip across easily.  The assembly could be bolted together with 1/4” bolts while everything else was being fitted.

The coat rack is still in use but not in my studio.  I don’t recall every using that type of joint again but it did work well in that situation.

Magnetic Rivet Holder

This little gadget may come in handy when there aren’t enough helping hands around.  It simply holds a rivet in place until it can be peened enough so that it can’t escape.  I have made a special clamp from vice grip pliers to do the same thing but this can be less awkward.

This magnetic holder was made from three short pieces of 1/8” x 1” flat bar to be used with 1/4” or 5/16” shank rivets which is the size I commonly use.  I keep a supply of 1/2” diameter rare earth magnets in stock so that is the size I chose.  They are a hair over an 1/8” in thickness.  These were gently tapped into drilled 1/2” holes and were secure.  Sometimes I have to use some adhesive to keep them in place in their socket.  I drilled 1/4” holes in the two pieces of flat bar backing up the magnet sockets so I could easily knock the magnets out if needed.

The rivet head socket is made by drilling a 5/8” hole in the center of the top bar and progressively smaller holes in the following two bars.  The last hole has to be small enough to prevent the rivet head from escaping.  I used a die grinder to bevel the drill hole edges to avoid galling the rivet head.  The bars are assembled with tacks on the ends.  They can be taken apart easily if something needs to be modified.

After all the bar assembly was completed the magnets were placed.  Gentle force is necessary to avoid fracturing the magnets.  Magnets can also be damaged by excessive heat.

These little magnetic wonders can be adapted to many uses but those who use them should be aware of their potential hazards.

http://www.rare-earth-magnets.com/t-safetyinformation.aspx

Vise Rivet Head Upset Tool

Usually rivets from 3/16” diameter through 1/2” are easy to obtain in commonly useful lengths. Custom rivets, for me, are either ordinary diameter rivets in an extraordinary long length or rivets with a larger than ordinary shank diameter.

I recently needed some 3” rivets with a 9/16” shank so I made them from scratch. Vise clamping and peening with torch heat works well but the shank needs to be gripped securely to prevent slipping. Providing a bottom buck works even better and combining the two is a sure thing.

Over the years I have made one style clamping/bucking tool to be used in the post vise which has worked well, That style is shown in images “Rivet upset tool 6 & 8”. The loop depth is about 3” as that is as long as I have ever needed. When making shorter rivets a piece of steel scrap can be inserted to make the bottom stop more shallow. On the 1/4” shank tool I actually tack welded in a stop piece.

After I had finished making a new larger version for the 9/16” shaft rivets I thought perhaps a more universal tool could be fabricated which would have a screw adjustable stop so I drew up a plan. I won’t take the time now to make and test one but if this comes up again I will try it. See “Adjustable Rivet Header”. The shank gripper part is made by sandwiching a piece of card stock between two blocks of mild steel and drilling the hole about the same diameter as the round stock to be used then relieving the sharp edges. The assembly is completed by welding the gripper jaws to the angle flanges and adding the side arms to the fixed nut creating sort of the bottom half of a turnbuckle. I will use 1” thread rod with 1” nuts for the adjustable stop. I might use a coupler nut for the fixed nut.

When welding clamp a piece of slightly oversized stock in the gripper channel so there is a little spring gap built in. The actual stock will fit easily and the vise jaws only have to bend the spring arms a little to grip firmly.

Tip for clean threaded rod end cuts:

http://www.woodsmithtips.com/2010/10/07/clean-threads/

Tip for upsetting rivets:

http://chestofbooks.com/crafts/machinery/Shop-Practice-V2/Simple-Bend-Forcing.html

http://www.persimmonforge.com/

Fire in the Hole

I like to use solid rivets. Emphasizing the joinery sometimes seems to dress up a piece which may otherwise be rather plain. They are a traditional or classical element whose use goes back to the Bronze Age.

Their nearly universal use in blacksmith tongs illustrates their advantage in being easily removable permitting repair and modifications.

If you do an image search for a rivet hammer, handheld type, not the air power hammer type, you will get the typical light cross peen variety. I’ve got a couple and rarely use them for anything especially rivets. A ball peen works best for me, at least in forming a rounded head. A flatter face is better for flush rivets or flat, low profile, ones. Maybe that’s what the rivet hammer is good for. The light weight which favors quick high velocity blows does make sense.

I only recently learned that in store-bought rivets the formed end is called the factory end and the one I form by upsetting, bucking, is called the shop end. That makes sense too. The shop end is also called the buck tail which seems to take a little more imagination to make sense. I suppose the factory end is the head and the shop end is the tail formed by bucking.

When bucking the factory end is supported by a rivet set to keep it steady and to preserve the head radius. I make mine by heating a block of steel and hammering in a carbon steel ball part way or using the press to do that. Various radius impressions can be done in a single block or individually. Incidentally some people seem to call the tool a rivet snap.

For most rivets I cut the shaft so the material available for upsetting is about 1.5 to 2.0 times the shaft diameter.

I usually slightly over-drill the rivet hole or slightly oversize the diameter with a punch or drift.

The out of usual context of this title occurred to me as I was heating a tenon in the process of peening. The punched hole was intentionally slightly larger than the diameter of the tenon so assembly would be easy but a tight fit was the goal. Directing the torch flame down the hole heated the base of the tenon, or rivet, so the following top blows would upset the shank to pretty well fill the hole. The next heats are directed at the tip of the tenon so it will mushroom to cover the hole and capture the bar. This is a small detail but sometimes important.

Another detail to consider with tenons, or rivets, and their corresponding fit holes is to make them both out-of-round, in other words, oval. There is extra rotational stability with this shape. Of, course it requires making an oval drift to prepare the holes. I’ve mostly used this on small items like delicate feet on small trivets.

In the process of making a lot of botanical stems I use a lot of 40d and 60d common nails. I use a cold stock shear to cut off the heads and gripper section. This leaves a lot of flat head rivet material. Common nails are tough and soft - I’m guessing about 1010 carbon steel alloy and work nicely as rivets.

I’m in the process of reworking some old inexpensive tongs which I picked up years ago in flea markets to form some more useful ones. I’ll likely have to make all those larger rivets myself. Fortunately I have some old rivet headers which I also found back in my flea market wandering days.

http://www.persimmonforge.com/