The Robb Gunter Demo
January 26-27, 2002
(report by Scott Little, ....)

Larry Crawford provided the usual generous hospitality in his Hammerfest Forge shop and mother nature gave us a pretty nice day...for mid-January.   The demo was well-attended including lots of folks from other clubs.   R.G. Box, winner of the touchmark auction, apparently set the distance record by coming all the way from Lubbock.

Robb started things off by showing us how to make a 1.5 lb slant-peen hammer. 

He started with a 1.25" square, 3.75" long block and, working from both sides, pierced it through with a narrow slitting chisel.
He then drove in a long tapered drift until the eye was about half-formed.   At that point, he used the drift, jammed in the eye, as a means of holding the hammer head while he proceeded to upset one end to make the face.  Note the slightly domed shape.  Robb likes to forge his hammers very close to net shape, thus avoiding a lot of grinding and sanding.

Here is the hammer head, completely forged and ready for final grinding and sanding.   Robb demonstrated a very effective technique for preventing the "lips" that usually form when you flatten the blank down to form the peen.   He simply drove the corners back into the stock at a 45 degree angle (i.e. chamfered them) before starting the flattening. He had to repeat this chamfering at several intermediate stages during the flattening but the end result was quite satisfactory.  Instead of the usual deeply creased "lips", his peen was almost flat across the face, ready for final grinding to a broad smoothly rounded peen.
Robb talked a good deal about identifying junk yard steel alloys and showed us the spark displays of a number of common alloys and some not so common alloys (like the big hunk of titanium that Larry Crawford produced, which created a shower of bright white sparks).  I think the one he's grinding in this photo was some 4340...i.e. 0.40% carbon.  Note the medium amount of sparks and the 3-4 "fingers" on the end of some of the sparks.

(photo by Jerry Achterberg)

Here's Robb rolling a scroll the hard way out of 1/4 x 3/4 rectangular stock.  He says getting the taper nice and uniform is critical to getting a nice-looking scroll.

Robb talked a fair amount about his super-quench formula and what he and the metallurgists out at Sandia National Laboratories went through to find the optimum formula (5 lbs of salt, 32 oz of Dawn Blue liquid detergent, and 8 oz of Shaklee Basic I in enough water to make 5 gallons of solution).  He doesn't claim miracles for it but he does make a good case for using it to greatly extend the usefulness of "mild" steel....i.e. A36.   Robb has found that A36 can achieve hardness of Rockwell C 40-43 when quenched fast enough.  That makes A36 a useful material for many medium-hardness tooling applications where high-carbon steel would otherwise have to be used.

R. G. Box of Lubbock won the online auction for a Robb Gunter touchmark and we got to see most of the process of making it.  This photo shows the master die that Robb carved by hand to create the pattern that R.G. submitted...a box.

NOTE: I personally witnessed Robb try  to make a chisel mark on the side of this A36 die for orientation after he hardened it with super-quench...and the cold chisel did not make any depression!!!
As he developed the master pattern, Robb tested it periodically by pressing a Pb disc into it with the vise.  Here are the proof discs that he made during the development of the R.G.'s touchmark.

After getting the pattern right, he used super-quench to harden the A36 steel and then proceeded to make the actual touchmark by repeatedly driving the yellow-hot end of a piece of 1/2'' Cr-V allen wrench stock into the master pattern until the pattern was fully developed on the end of the hex stock.

He then hardened and tempered the hex stock and presented the finished touchmark to R.G. Box.

Robb has made a lot of touchmarks this way and he brought along a collection of the Pb proof discs that accompany the production of each touchmark.

 The last thing Robb did on Saturday was demonstrate his technique for working ordinary black iron pipe into things of grace and beauty.  Here he is forming a "bucket rim" on the end of the pipe.  To do that, he first flares the end of the pipe by working it hot over the tip of the horn and then he spreads and flattens the flare by hammering directly onto the open end of the pipe, then he goes back onto the horn and rolls the flared end over tightly like a bucket's rim.
Here's the finished pipe piece after Robb worked a nice gentle taper into it and then curved it simply by hammering on it.   Robb likes to make such curves by working "in air" with one end of the pipe supported over the anvil horn but hitting the pipe only in the unsupported area next to the anvil.  With care only a minor amount of flattening occurs and that can be corrected by a few hammer blows on the sides of the pipe (supported on the anvil face).

Gary Hilton submitted this info about the auction Saturday night:

This auction was very successful with the tools that the Panaks and Tandy donated bringing good prices.  Robb’s hammer was well received.  Al Morgan’s rounding hammer and tongs donated by Jim Galish were highly thought of.   Shannon ’s crown was bought by Stretch for a bracelet.  Jerry’s peewee tool sets sold off quickly with Robb bidding on the small rounding hammer, although someone else bid a bit higher.  Harvey’s lamp and bar-b-que set went out very well.  Charlie’s hummingbird was bought and given to Helen Wise.  Robb’s leaves went to James Honig and Wendell Broussard I think.  In fact the bidding got so hot the overhead projector was auctioned off.  Robb’s friend Karl donated a hammer that was bought and given to Wendell Broussard.  Larry Stevens’s three pair of tongs went as a set.  Larry Crawford ’s towel rack and curtain rod hangers were bought.  This is probably not all but in general people were generous with their donations and the buyers were there with plenty of money and the desire to spend it.

Anybody got anything to say about what Robb did on Sunday?  If so, send it to me (Scott Little).