patchbox spring

[FALout]

I've been making springs for opening the patchbox lid ( not for the latching), without success.  Having never handled an original rifle, I'm not sure that all of them had this spring or if it's really needed?  It's just a flat spring, I've seen them made before, but I'm not getting it doing this on my own.  Either they are too brittle and break or the temper is wrong and the spring just bends with pressure.  Any help or knowledge would appreciated.

[mjm46@bellsouth.net]

I've made a few using pieces of hack saw blade. You can carefully bend a piece of hack saw and it will stay bent fine for opening the box. I have even made latch springs with hack saw, and these I heat treat by heating bright red then bending and then reheating bright red and quenching in water to harden then just heat in the torch very briefly and let cool to temper. works well although very unscientific, but worked well all the same. Old saw blades are cheap and plentiful and easy to work.

[Mark Elliott]

First, you need good plain carbon tool steel.   Buy the flat strips of spring steel that Brownells sells, not the stuff in the tubes.   1/32" will work fine for all the springs in a patch box.   I generally make a V spring of sorts for my catch springs.  It really depends on what type of gun you are making.  You should use the release mechanism used by the maker whose style you are imitating.    Assuming you have formed your spring making sure to polish both sides and form it red hot without overheating it(past salmon color), heat the entire spring evenly with a MAPP torch or in a forge to a bright red or salmon color.   When you have an uniform temp as indicated by the color,  quickly quench in oil.   I use either actual quench oil from Brownells or 20W motor oil.   I have been using the same oil for many years.    Check with a file that the entire spring is hard after the quench.   The most critical part is next.  You must temper the spring at 650-700 degrees.    The best way to do this is a heat treat oven.   I soak the spring at temperature at least 30 minutes.    If you don't have a heat treat oven, then a tried and try way to get the temper right is to use a thermostatically controlled lead pot.   Heat the lead until it JUST fully liquifies.    This will probably be around 650 degrees.   You can check the temp with a lead thermometer.    Just drop the spring in the lead and leave it there 15 minutes or so.   Take it out, let it cool, and you should be golden.    I was making springs like that when I was in my teens.   

[Acer Saccharum]

This little spring for opening the lid should be fairly good steel. 1075 or 1095 works great. Or an old flat spring re-used from a lawnmower recoil starter, or some such equipment will work. But if you're going to be messing around for a long time finding suitable material, just buy some sheet spring steel from Brownell's or Dixie. Works like butter when annealed.

Installed spring, without patchbox in place:



A finished installation:


The long spring for the catch can be mild steel; it has so little flex, it never goes out of shape.Used just as is, mild steel has plenty of spring for a catch.

[pathfinder]

That's how i do my small spring's too,in the lead pot. I think Kit Ravenshire used this method. Work's GREAT! Thank's Mark.

[FALout]

Thanks for the replies guys.  I had forgotten about using melted lead, will make another one and try that method.

[Jim Kibler]

Little springs like this made out of thin material are very forgiving as they aren't highly stressed.  Material isn't terribly critical for these springs.  Since they are so forgiving, re-used material usually works fine.  Harden and temper to a blue or a little beyond and try it out.  Should be fine. 

[cmac]

Steel yard rake, music wire, files,etc...

[McClary]

One method that Kit Ravensher recommends that has worked well for me is to harden the spring by quenching in oil then put it in a small metal can and just cover it with 30 wt. oil. Heat the oil with a propane torch until the oil ignites, let it burn completely out and when cool the spring is tempered correctly.

[FALout]

McClary, that's the method I've been trying to use without success.  It could be what I'm using, I can't remember where I got some of this stock, it's been sitting around for some years and maybe something else got mixed in.  I'm not giving up, just frustrated.

[Dennis Glazener]

I have used steel lumber bands for patchbox springs, worked well for me.
Dennis

[Hungry Horse]

I am the spring steel scrounger from $#*!. Anything that looks like it might make a spring, comes home with me, just ask my wife. I have used old recoil springs from small engines, old clock springs, antique phonograph springs, replacement springs for pruning shears, old hack saw blades, and my favorite, spring fingers from a walnut huller,( they are exactly the right size for revolver hand springs. I don't think I've ever bought any spring steel new.
 I temper them by color, and have never had one break in use.

                    Hungry Horse

[bgf]

If it is either too brittle or too soft when you finish treating it, it must be somewhere in the neighborhood of proper steel!  Too brittle means it wasn't tempered enough; too soft mean it wasn't hardened or was tempered too much (too high heat).

Harden as Mark Elliot says, then temper.  If you don't have the oven, use the burning oil method -- I don't know how, but it always works for me, even when I went "green" and used vegetable oil for it.

[Acer Saccharum]

First the spring is hardened. Then polish it bright.  After that, I just play the burnz-o-matic torch over the spring until it's the proper blue(subjective). sometimes you have to tease the part with the torch to get the color just so. Dark blue seems to work for me with 1095 or 1075, but 0-1 tool steel should be taken to light blue(a little hotter than dark blue)

Range of tempering colors:
straw, brown, purple, dark blue, light blue
The colors have a corresponding temperature, but I don't know what it is.

[Dr. Tim-Boone]

As Dennis said, steel packing bands from lumber or from furniture cartons works well. For a catch spring or a simpler door spring you can bend it as needed (carefully) without heating.... it doesn't take much for these simple springs. 

[Acer Saccharum]

Sometimes I make more work for myself. 

I like to drill a hole in the end(see photo above) and that sometimes requires the stock to be annealed. Or the steel hardens more while drilling, and needs to be annealed. Then the shaping, I like to do that hot, as I get sexier bends in the springs than if it were done cold.

But read thru this whole thread, and you'll know how you're going to proceed, OR be completely confused! Hahahahhahahaha.

Tom

[JCKelly]

For what its worth, I asked & Brownell's recently told me their spring steel strips were 1095

I got some 3/32" 1074/1075 SHEET from mcmaster.com for a small project.

Don't personally know where to get 1070 - 1075 strip

[bgf]

First the spring is hardened. Then polish it bright.  After that, I just play the burnz-o-matic torch over the spring until it's the proper blue(subjective). sometimes you have to tease the part with the torch to get the color just so. Dark blue seems to work for me with 1095 or 1075, but 0-1 tool steel should be taken to light blue(a little hotter than dark blue)

Range of tempering colors:
straw, brown, purple, dark blue, light blue
The colors have a corresponding temperature, but I don't know what it is.

I have found this useful several times, although I think color is somewhat subjective:
http://www.anvilfire.com/article.php?bodyName=/FAQs/temper_colors.htm

This one also:
http://www.anvilfire.com/FAQs/temper_colors_hardness.htm

The oven or burning oil methods take a little longer than polishing and going by color with the torch, but I'm more confident of the results with them; that's just me -- whatever works is fine for PB springs!

[Bob Roller]

I bought 50 lbs of 1075 sheared to a specificed width from Lapham-Hickey earlier this year.
It is 1/8" thick and I use it for mainsprings.This was in eight foot lengths and the UPS was bordering on
piracy but such is life I suppose. I also use 1075 in 3/32 and .030 for set triggers and .187 for sear springs.

Bob Roller

[StevenV]

Attached are some photos of patch box springs from current build.The "kick out" spring for the lid is from 1/32 spring steel from Dixon's . I cut spring shape, then drilled hole. I heated to bend to shape. Then I heated until metal was non- magnetized, and quenched in 30W oil. Then I placed spring in small can and covered with 30W oil about 1/4 in above piece. I then lite it on fire and burned until all oil was gone, spring was tempered. The spring for lid latch release is from 3/32 spring steel from Dixon's. I cut and filed to shape. Then heat to bend to desired shape. I never tempered this since it already has spring in it and the travel is less than 1/4in. . Both springs work great.[.jpg[/IMG]