Vol.12 / Issue 7                              Tennessee Valley Woodworkers                             Editor, Richard Gulley                                     July 1997

Happy Independence Day to all you wood-chuckers! July is a great month for grilling and watermelons and homemade ice cream and would be a great month to clean out my shop - any volunteers?

I do plan on cutting back on computer time and increasing my shop time. This startling turn of events is due in part to the "Magic in Wood" exhibit. I was impressed! More on this later in this issue.

Before we get started with the real goodies I would like to put out a plea for excess garden commodities (cucumbers in particular - good canners specifically). My youngest daughter has developed a desire to put up pickles and kraut and I didn’t plant cucumbers or cabbage. If anyone can help me out let me know. By the way, my daughter’s desire for pickles and kraut has extended over the last several years with no sign of morning sickness. I think my position as baby of the family is safe — for now.

Last Month

Several visitors / new members were introduced. New members included James and Sheila Cook, Thurman and Fern Farmer, Charles Walker, and Jerry and Liz Payne.

Report on Exhibit: The exhibit has gone well at Foothills and at the Tullahoma Library. On Tuesday, before opening, there were about 20 visitors signed in. The statistics are 49 entries from 26 people, not counting last minute entries in Winchester.

Report on Fall Workshop: Only activity this month has been mailing out letters of confirmation to Pat Matranga (professional woman turner from Nashville) and Dr. Richard Binger (segmented bowl turner from Huntsville). Note: The date is firmed up as October 11th.

Falls Mill Artisans day: Date is August 30. Janie Lovett collected names of the people who will participate.

* The picnic is set for September 20. * The Holiday party is set for December 6.

Show and Tell:

*Bill Knight __ Turned bowls with tops and a story.

*John Sargent __ Turned segmented bowls

*Tom Cowan __ Pedestal for multi_level table

*Henry Davis __ Bowl turned from local hardwoods by his daughter by marriage. Henry also gave us a lesson in how to turn the bowl bottoms.

*Winfield Bennett __ Braces built by Charles Knies in the 1920s. Also a Tramp Art piece he made from paint paddles.

*Loyd Ackerman __ beginner's bowls

*Dale Jones __ Lazy susan

*Bob Reese __ Rocking horse with straight section to keep it from tipping over backwards

*Ben Whitaker __ Foot stool made from Woodsmith plans.

*Jim Van Cleave __ Ivory handbag closure, hole saw collectables, Brass backsaw

*Manuel Brown __ Chest and shelf unit from 1970s made from Popular Mechanics plans. Also, guitar made in 1974.

*James Cook __ Carvings that "bring people out of the wood".

*Crocia Roberson __ Manacala box and a story from 4H camp.

*Jim Roy __ discussion on use of Polyshades thinned down to make rubbing varnish. Also, sanding sponge and detail sander (Skill).

*Doyle McConnell __ Flint Lock rifle made a long time ago.

*Irma Troxler __ One of 4 pieces of a stamped cross stitch quilt.

*John Troxler __ Colonial cutlery tray, Block puzzle, candle stand from civil war era.

*Richard Gulley __ Extra Splinters copies, Planes, and marking gauge

// note: I can't recall who followed me or what he showed. Maybe you can fill in from your recollection.

minutes by Loyd Ackerman

Dear members,

Thanks to all who participated in the Magic in Wood exhibits during the past month, either as an exhibitor or an attendant. Everyone seems to have enjoyed it - participants and viewers. As Tom Cowan said, it benefited the club by providing a unity of purpose and lots of camaraderie. And, hopefully, we’ll gain a few new members.

I’d guess we had about 700 visitors though that may be a bit optimistic. Comments were very positive at all three locations and several expressed interest in having projects built for themselves.

I do anticipate doing such an exhibit again sometime. Therefore, we should document some of the things we did and some of the lessons we learned. If you have constructive comments we hope you jot them down so that the next exhibit can be bigger and better.

Ross Roepke, Co-Chmn

Loyd Ackerman has a Delta 12" planer for sale for $250 and a Shopsmith with accessories for $1,300. Both are in good shape and can be demonstrated.

(The following is an article by Ron Hock that I found on the Internet - where else?)

I posted this some time ago when the group project was the St. James Bay plane "kits" and some were (bravely) doing their own blades for them. It's doable; get some extra pieces of the same steel to practice on...

The only addition this time around has to do with the great question of which quenchant to use with which steel. The steel used in any given blade is not an easy thing to determine. A metallurgical lab charges a fair amount to test for alloy and there is no home test kit that I know of ("Look, Honey, it turned blue!") And there is some risk in quenching, say, an oil hardening steel in water. It could fracture at worst or warp like crazy at least. The old_timers "sparked" steels to tell what was in them. The sparks generated from a grinder will burn with different visual characteristics depending on the alloying elements. (Like the different colorants in fireworks.) So you can grind a corner, observe the sparks, then grind a known steel and try to compare the little spark_flares for shape, brightness, complexity, etc. and attempt a match.

Mostly we're talking oil vs. water hardening steels. The air hardening ones are the Cr_V and stuff that us Galoots don't use too much and that weren't used in old tools at all. It is safer to quench an unknown, perhaps water_hardening steel in oil than vice_versa. The water_hardening steel may not harden in the oil and if that is the case, you can try again in water. I don't mean to muddy the water with all this but, hey, if it was easy, everybody'd be doing it.

Okay, here we go again:

The first step is to get the metal to its critical temperature which with good old O_1 (the oil hardening stuff) is 1450 _ 1500F. Got a good pyrometer? No problem. For some reason (let it be a mystery; there are so few left) steel ceases to be magnetic at that temp. This phenomenon is called the "Curie Point" after the discoverer, Pierre. So one can simply heat he metal till the magnet is no longer attracted to it then quench in oil. I like to use peanut oil because the flash point is very high which minimizes the risk of fire (the risk is still there, tho; be prepared: use long tongs to handle the work to keep your hand out of the way, wear gloves and keep the fire extinguisher handy) and it smells nice(r) when it smokes.

How to get the blade to the Curie point is probably the biggest problem for the DIYer. When the metal is glowing red, the carbon behaves as if it's in a liquid and can therefore migrate around as it pleases. This is necessary for the hardening to occur but near the surface of the metal those unfaithful little carbon atoms would just as soon run off with any available oxygen_sluts it runs into (oxygen is soooo seductive) and they're lost then forever. We hate that. We attempt to prevent this by: heating the metal in an inert (oxygen free atmosphere) and/or limit the time at red_heat (in air) to as little as possible. A torch makes both of those very difficult. It's very hard to heat something as large as a Norris_type blade evenly with a small torch_generated spot of heat. A forge fire is better because of its uniformity and it can be starved for air a bit to decrease the oxygen in its immediate vicinity. A small lab_type test oven works quite well. (Also used for ceramic glaze tests.) Toss in a charcoal briquette to scavenge some of the oxygen.

When it's hit critical temp, remove it from the heat and quickly dunk it into a sufficient quantity of oil (preheated to about 150F.) Swish it around a bit until it's cooled then let it cool to ambient in the air. It should now be very hard and too brittle to use. (If you attempt to file it, the file should skid on the blade.)

Two ways to temper to a useable hardness /toughness: by colors or by temp. If you have a very accurate oven in the kitchen, just heat it to 325F and you're done. An accurate deep_fryer will do the same. But without the accurate temp control, you'll have to use the surface oxide colors to know when enough is enough. First, clean some part of the blade (probably the flat area back from the bevel) till it's bright metal again. When heated, that spot will change colors (you've seen the rainbow of colors on any overheated steel) starting with a very faint yellow (called light straw). Since we like our blades Good_n_Hard(tm), stop there (remove from the heat, quench if necessary to stop any further increase.) Any color beyond the faintest straw is too much. (The blade will still work, it just won't hold the edge you want.) Be overly cautious with tempering. You can always re-temper a too hard blade, but if you go too far and soften it too much, you have to re-harden it all over again. So if a blade seems too hard, just toss it back in the oven and go a little higher.

You're done. If the blade looks awful, you can sandblast or grind it pretty but it should work well regardless. Before honing, be sure to grind back the bevel a bit. That thin section probably took more than its fair share of carbon burn_out abuse and you need to get to the good stuff. Same for the back. Doing a good job on the back is at least if not more important than the work on the bevel. A little extra elbow grease will remove the de-carbed layer and get to good metal. On any blade used bevel down, the back IS the Cutting Edge. Think about it. If the back hasn't been honed deeply enough, the blade will never work well.

Ron Hock (rhock@mcn.org)

Hope you’ve enjoyed this month’s SPLINTERS. Let me know if there’s anything you’d like to see here (short of Cindy Crawford) <grin>

Looking forward to seeing you all Tuesday the 16^th at the Duck River Elec. building at 7:00 pm. Bring a friend and remember --