Found A Sheet Metal Shear That Needed A Small Repair.....

[brino]

Hi All,

Last week I was at my favourite local tool store browsing the small tools, when the owner says "Hey weren't you looking for a shear?".....I was....and wasn't...... I mean it's on my "someday tools" list, but I don't currently have the space for one as large as I want.

Of course I always love looking at tools, so I went out to another building and was shown a Brown Boggs 249B 48"16 ga. sheet metal shear and also happened to notice a Chicago sheet metal brake parked beside. Both had asset tags from both a local aerospace and a local instrumentation company (one company had bought the other).

Here's a shot of both. The shear is in the foreground, and the brake behind:


As you can see that building has stuffed packed in. Those crates were stacked twice my height.

He then continues to say that he is currently over-stocked, has no room for more stuff but has ten more shops worth of equipment to bring in. I looked, took a few photos, and said that I could not buy them without first figuring out space and talking to my wife about the financials.

As usual my wife was very supportive. She said I could find the space if I had to, and she knew that both were on my "someday tool" list. She's a keeper!

So I called the tool store and arranged to pick them up mid-week. What better reason for a vacation day, right?

Stay tuned for a small repair required to the shear.....

-brino

 

[brino]

I got what I thought was a decent bundle price on the two pieces, because one needed a small repair.

The shear is treadle powered and has two pockets on each side to receive the treadle bar. On the right-hand end the front pocket had the top broken off. This is a strange place to break, as the bottom of the pocket gets all the force from stomping on the treadle. The seller thought it broke because the bolt wasn't tight and the treadle rebounded on release. I believe that the treadle bolt in the pocket was over-tightened.

Here's the broken treadle pocket:









more to come.......
-brino

(By the way, I did get all the fingers for the brake, though they were not in the original photo.)

 

[brino]

So the good news was that it was a clean break and I had the part that broke off.
After thinking about my options:

1. arc weld (smaw) using special cast-iron or high-nickel rod,
2. braze with oxy-acetylene using bronze rod,
3. tig weld(gtaw) with silicon bronze rod

and re-reading all the great input at this thread: http://www.hobby-machinist.com/threads/welding-cast-iron.42577/
I decided I would go with option #2. Hopefully I could keep the heat down and not need preheat and slow post-cooling, and I need more practice with tig before I try anything that matters.

The piece broken off from the pocket top was obviously cracked from the hole out and had a small offset at this crack. When I straighten it to get both side of the crack flush, it broke again about 90 degrees from the first break. It must have been cracked there too, which is why I believe it was broken from over-tightening.

I ground a vee on one side and brazed it, then turned it over and repeated the operation:




I did some clean-up grinding on this top piece and then checked the fit.....

-brino

 

[francist]

Nice find! I'm especially envious of the D&K brake -- or at least the fingers thereof. I have what looks to be an identical one but minus all the fingers. One of these days... .

-frank

 

[brino]

With the top piece of the pocket ready to go back on, I ground vee's in both pieces leaving enough of the original broken surface to provide a good registration of the pieces.
I was not overly concerned with getting 100% penetration, because the top of the pocket should not take too much force.



I have no pictures of the rough, raw braze, but here it is after being cleaned-up:




After grinding, I did notice it was not perfect.....I had some small voids near the top of the vee.
However, if I ever get around to re-painting, it should be at least as good as the other end:


All comments are welcome.
Thanks for looking!

-brino

 

[brino]

...ooops almost forgot.

I used a small burr to grind back the bronze in the threaded hole, and then cleaned-up the thread with a tap.

Here it is re-installed and functional.


Those pieces are fresh cut. The shear is back in business!

I would be very interested in copies of any manuals for any Brown Boggs shear......operators manuals or parts diagrams, anything!
Specifically I'd like to know about the blade and return spring adjustment procedures.

Thanks!
-brino

 

[jpfabricator]

Nice score!

Sent from somwhere in east Texas by Jake!

 

[woodtickgreg]

Nice score and great repair! I enjoyed seeing the braze job on the cast.

 

[FOMOGO]

Congrats on the new acquisitions, and nice fix on the casting. Mike

 

[Bob Korves]

Nice work on the brazing job! That was definitely the best choice from my viewpoint.