Here is a little contraption I made for effortless blueing of screws and hands. A good friend of mine made one and I knew I had to copy him. It uses a temp control that can be set to hold a certain temp closely on a brass block. A ten buck thermocouple, 200W heater, brass block, $25 dollar PID controller, 6x6 electrical box, relay and some wiring. Dark blue (570F), plum (540F) or gold (450F), easy as can be, just set the temp. I drilled a number of different sized holes for screws and milled a larger hole for hand hubs so they lay flat. No more watches a blueing pan intently, or having hands overblue at the tips....
Posts: 352 | Location: Scottsdale, Arizona USA | Registered: November 25, 2002
I have industrial oven with same temp. controler on it, just wonder if the oven will do same trick as your brass block? . How long the screw or hand need to be on that block in minutes to get the color ?
Posts: 4395 | Location: Arizona in the USA | Registered: July 23, 2011
Most of the needed parts came from Amazon, PID control available for $18 to $36, Solid State 20A relay $10, Ktype thermocouple $3. The 120V 150w or 200W cartridge heater from Ebay around $10. The brass block I already had, 6x6box came from Home Depot. Even though I have the brass block an inch and a half off the base , the base still gets really hot. Someway to heat isolate it would be nice.....
Posts: 352 | Location: Scottsdale, Arizona USA | Registered: November 25, 2002
The problem is that the bolts are transferring the heat. Here is a cheap and easy way to isolate the heat. Get a terracotta dish that goes under a flower pot. Drill 8 holes in it with a masonry bit. Bolt the block to the dish with 4 short screws in 4 of the holes. In the other 4 holes bolt the dish to the base. Make sure not to over tighten the bolts or you will crack the dish. But you can get them real cheap. It wont get rid of all the heat, but it will get rid of a lot of it, the more space between the bolts the better..
Posts: 1143 | Location: Chicago, Illinois in the USA | Registered: September 05, 2010
Paul, search for; Amazon, 1/16 DIN Dual Digital F/C PID Temperature Controller SSR(2 Alarms)$23.19 Amazon, 250V 25A SSR-25DA is the relay number $9.20 Amazon, 1M (3.3ft) K type Thermocouple $2.50 Don't drill/tap hole to deep or it won't lock in place. Amazon, Amico AC 110V 200W Cartridge heater 8mm x 50mm. $2.99 Drill hole clear thru the block, make sure the cartidge htr is snug for proper heat transfer. If it is loose, it will burn out. I would also mount the PID in the lid of the electrical box if I had to do it again, it would be easier to read the temp.
I used 10-32x 2" long bolts for mounting the brass block, some way to block the heat transfer from the brass block would be ideal, but not totally necessary. Drill the block with a bunch of different size holes so it's easier to observe the screws and a couple shallow holes for the hand hubs. Remember, the more polished the item the better the result. Also, wax,polish, grease, sweat or anything else must be removed before bluing. One more thing I noticed, I had a fan going pretty strong on a hot day and couldn't get the right result on a case screw, a breeze across the heating block is to be avoided. The Chinese to English instructions that came with the PID are as clear as mud, and it took some fiddling to get it figured out, don't know if the more expensive PIDs have better instructions or not.
Posts: 352 | Location: Scottsdale, Arizona USA | Registered: November 25, 2002
Here is my finished blueing tool. Thanks for the help Harold and Peter. I had quite a time getting the parameter set. The seller contacted the MFG for me and got it straight. The unit maintains temp. with 1deg. Last picture is just messing around with a cotter pin. Great results i think. Paul
Posts: 122 | Location: Baltimore, Maryland in the USA | Registered: February 25, 2011
Peter, If you want the whole center part not to be blued, I would think that high heat paint, like the Krylon high temp spray paint good for 1200 degrees, would work though I have not tried it. Just spray some in the cap and dip the hand end in it and let dry before blueing. Dip the hand in acetone to disolve the paint. I have done pallet fork and roller jewel replacement with the blueing block, set the temp at 195 to 200 degrees, shellac will be nice and soft to make manipulating the jewels an easy task. Harold
Posts: 352 | Location: Scottsdale, Arizona USA | Registered: November 25, 2002
Even though I have the brass block an inch and a half off the base , the base still gets really hot. Someway to heat isolate it would be nice.....
Harold, First, really nice work!
This may be too late, but I just saw this.
A couple ideas to try to reduce heat getting to the base: At 570F there's a bit of radiative heat as well as conduction and convection. If you're just trying to reduce heating of the base, you could put a heat shield (piece of sheet metal a little bigger than the brass block) about half way up the mounting posts/bolts. It might be better, however, (not to mention safer) if you were to fabricate a 5-sided heat shield that surrounds the sides and bottom of the brass block with about 1" of space all the way around. That should keep everything below touch temperature (~50C). If there's still too much heat conducted through the bolts, using a second stud or turnbuckle to thermally isolate the posts from the block would help.
Just a thought.
Evan
Posts: 995 | Location: Pleasanton, California in the USA | Registered: September 22, 2012
So, did anyone else make one of these? I am having the toughest time finding a brass block. I showed the pic to Home Depot and got the funniest look "um ... brass block? ... try plumbing."
At any rate I have all of the Amazon parts, think I can find a good mounting board, and the electrical box will be different, but the brass block is not that easy for me to find. I almost bought a brass plumb bob with the intent of squaring it off ... then tried to find a brass hammer ... so I am stuck. I would just like to hear how others went about building this wonderful tool!
Posts: 407 | Location: Northern Virginia in the USA | Registered: October 08, 2011
I have not tried the machine shop route, so that might work. I have been looking at places like findingking and amazon, so I did not think about just a plain metal seller search. Thanks for the replies! I will give these a shot.
Posts: 407 | Location: Northern Virginia in the USA | Registered: October 08, 2011
I found an online company called Speedy Metals which sells cut lengths of brass and a lot of other metals with no minimum order. Just for comparison a 2 1/2 " cube of brass goes for about $60 while the same size aluminum is about $10 before shipping.
Posts: 346 | Location: Woodland Hills, California in the USA | Registered: January 07, 2011
I ended up getting a 6 x 1.5 x 1.5 inch piece from someone. Paid $30 and used a hack saw to cut the part down to 2inch by 1.5in by 1.5in. drilled holes and mounted the entire thing. I mounted the block in an aluminum tray and the bolts are mounted to the tray, so it is basically floating about the wood (the other side of the tray is mounted to the gray electrical box). There is about an 1/8inch clearance between the aluminum tray and the wood. Also the block is not mounted to the screws, rather it has holes drilled that are a bit larger than the screws and it is sitting on those. This reduces the amount of things that can conduct heat away from the block, keeps me from bumping the block, won't let heat travel to the base, and gives me a place to catch things if they drop off the brass. Don't get me wrong, at 570 degrees Fahrenheit the aluminum still can get HOT, but it is better than nothing. I have been using it off and on for several months now. I have since added an on off switch. Here is a pick of the machine, and some test items (broken balance staffs).
Posts: 407 | Location: Northern Virginia in the USA | Registered: October 08, 2011
I think Harold's little cooker is excellent. Just wondering if anyone has tried building one using a block of aluminum 6061 instead of brass? Easier to machine, great conductor, much much cheaper. What does everyone think about that idea? By the way, nice job on your 'cooker' Dan C
Posts: 29 | Location: Buzzards Bay, Massachusetts in the USA | Registered: November 15, 2013