Crossbow repair

[bplayer405]

Had a friend and fellow hunter call with an issue last night. He took a shot at a doe and missed low. He proceeded to recock his crossbow and the foot stirrup broke and wondered if I could help. He brought it by this morning for me to check out.

The stirrup had some light welds to hold it together, but the material was pretty minimal in thickness to hold back 185 lbs of draw weight to begin with. Two points of attachment roughly 1/8" thick and barely 3/16" wide at close to 90° of torque imposed on these points. Part of the welds failed and what material was left intact snapped off the base.

I cleaned up the base plate then found a length of 1/4" rod and proceeded to bend it up like a small coat hanger. Made some hot solid welds all around the rod's contact with the base and cleaned it up to fit the bow with no problems.

He got the chance this afternoon to try it out and says it works well. He'll paint and plasti-dip the rod section when he gets the chance. Best thing is that he can get back to hunting asap and not have to wait for a replacement part. Love how a bit of ingenuity and welding fab can save the day...

 

[Gary Fowler]

A lady is supposed to bring me an old fashioned lawn chair that one of the steel slats has broken. I will attempt to weld it with my Titanium 125 if it is thick enough otherwise I will get out the TIG torch and weld it with that. Her husband just bought $2000 worth of my used implements so I dont know if I should charge her for the welding or not.
I do have a sign out for welding shop work but no hourly rate. I think $50 per hour with a $20 minimum would be a fair price. A local mechanic shop has a $60 per hour charge.

 

[bplayer405]

Used my Titanium 125 today on the job welding up angle we're using to help retain a line of 1 ton blocks. Gonna be a retaining wall at a lake front. Supposed to build a gazebo and a new dock also. Anyways, was having some issues with the Lincoln wire on the butt joints. The pool acted like it was boiling out slag. I cleaned the mill scale off so that wasn't the issue. Wonder if the wire has been moisture compromised. The first inside corner weld went well. The butt welds were quite different though...
View attachment 1325

 

[Yomax4]

Yep. Sounds like it's been on the shelf too long. It starts to act like hard wire with no gas when it goes bad.

 

[bplayer405]

Weird. Still my first roll of it. Been sitting in the machine a few months though...

 

[Gary Fowler]

I havent had that experience so far. I made my first welding shop sale yesterday. A lady had an old antique steel slat lawn chair that a couple of the slats were broken. It was all rusted, flaking paint, dirt and who knows what else. The slats were about 2" wide by 1/16" thick and both had about 1/4" gap between the breaks. The first repair, I backed it up with a 1/32" piece of galvanized sheet metal. It welded OK but the backer was easily burned thru. The next one I used a bit thicker backer plate about 12 gauge plate and it welded up much better.
I was only doing it for fun and a favor since her and her husband just bought all of my old unused equipment items that I had for sale. I had an 8' bush hog, an 8'tandem disc and a 6' box blade that went with my LS tractor sale. The LS was 10 years old and only had 193 hours on it so I decided to get rid of it and free up some shed space. Now I park my B26 in that shed and put my 20' trailer under the other side shed at my shop. Yesterday I sold a 2 row cultivator, a 5 foot light weight back blade, a 6' tiller , a 5 foot subsoiler, 8' landscape rake and my 40 year old row hippers all to the same man.
That left me with only a 4 foot back blade and a home built 3 PH hay spear to get rid of to clear up all the unused stuff. Most of the stuff I priced at what I gave for it 10 years ago, some of it was given to me so I let that go really cheap.

 

[bplayer405]

Took the time yesterday to run that welder on some scrap the same as I did welding up that angle and the same thing happened. No slag coverage on the weld, like its boiling it off and leaving holes in the weld.

I tried a different wire spool and another brand (hobart) that was fresh from the package. No difference. Way more spatter than I remember from this welder also. Recommended setting is very hot, tried down to half of those settings with not much difference. Last pic is Lincoln wire on the left Hobart on the right (ran opposite directions).

 

[Yomax4]

You are running electrode negative right? is this 71T-GS or 71T-11 ? . The -11 runs 10x better than TGS

 

[Yomax4]

You don't always get a complete slag covering on the welds. It's kinda all over the place. Your spatter looks terrible. What size spool or wire are you using? 2# -10# ? 035?

 

[bplayer405]

It's the Titanium 125 fc only machine. Can't switch polarity. Lincoln NR211-MP and Hobart E71T-11

 

[bplayer405]

2lb .030

 

[Gary Fowler]

That underbead porosity (visible from first photo) is indicative of moisture in the wires flux. You can get the same problems with a 7018 electrode if it is moisture laden.
Just for giggles, spool off several feet of the FCAW wire, twist it up to make a larger diameter and then arc it out (using a stick welding machine) with just enough current to make it glow red hot but dont leave it arced out long enough to melt. You will be looking for a puff of steam released just as the wire starts to glow. IF you get that, then the wire has moisture in it. The reason for twisting up several feet is to get enough of the flux to make the moisture escaping as steam to be visible. You can do the same thing to LH rods to dry them out if they have been exposed to moisture for a period of time.