VN VN12 Overarm Bar Won't Budge

+1 on Dredb- do not hit it with anything.

This may sound simplistic, but make sure that tightening tang on top is loose, if not removed.
 
chips&more said:
Your uncluttered floor space beautiful. I have just the opposite. Forget the flu that’s going around. I need help with toolaholic pile making disease…Dave.
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It was photoshop'ed. It is an illusion. :grin big:

Another vote here for the Kroil. I've seen loosen up items that PB and LW didn't.
 
I worked on a 1953 No. 12 that had a siezed support bar. The first thing you want to do is get it to rotate, that way you know you've broken the rust free. I used a HF blind hole puller to get the split-cotter clamp apart:
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That lets you get penetrant into the clamp area. A 50-50 mix of acetone and automatic transmission fluid works about as well as anything, Kroil included. You want to make sure the blind end of the cotter clamp is free. Put the clamp bolt back in and tap on it to break the clamp free from the bar. There are two split cotter clamps: one horizontally in the front, the other vertically in the back.

We were able to use the overarm support casting to break the bar free, using a dead-blow hammer:
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Just some light blows until we got it broken loose and rotating 360 degrees.

Then we used some light blows against the back of the bar with a wooden block and sledge to tap the bar forward. We were NOT beating on the bar, just controlled blows to impart some momentum to the bar, with the sledge held as shown with ONE hand.
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It was a process of me rocking the bar side to side and my buddy tapping on the end just enough to get to slowly move.

As far as a setup to press the bar out, I would rig up something that uses two lengths of 1/2" all-thread. You can get a 10 foot ong piece of 1/2" electrical support rod from home depot (in the electrical department) for about $10 link. Make a rectangular structure that fits around the bar, bearing against the front of the ram and extending beyond the machine on either side. Put beam of some sort across the back end of the bar and connect either two end of the beam to the box with the all-thread. Tighten the nuts alternately until it moves. A box and beam made of 2x6 lumber on edge might be enough to do the trick if you add some steel plates to distribute the load where the nuts bear. If you can't picture what I'm suggesting, holler and I'll draw a sketch.
 
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Thanks to all for the pics, links and advice. Real nice group here.

I was reluctant to ask - but glad I did. Sort of embarrassing how long these parts have sat with no real progress.

Cold outside and a busy weekend, so it'll be later next week before I can try anything that takes any time.

Quick peek down the back wedge lock hole tells me there's rust on part of the back half of the lock and it's still jammed against the bar. After I break that loose I have a lot of bar cleaning to do before I try to move anything. The good news is that I haven't damaged the bar with my wood block/mallet and I did wrap the bar with some scrap aluminum before I locked the chain vise-grip onto it.

I've been filling the lock holes with PB blaster on and off for a few months now. Once the rear inner lock is loose and the bar is clean I may try some other fluid, just to see if it makes a difference. Also have to look around to see what I can cobble together to apply heat to the case and to get some real pressure on the end of the bar.

Thanks again for all the help.
 
When I was over in the UK the host over there told me he uses Citric Acid mixed with water to remove rust. He said most rust removers as they work the rust swells but with citric acid it dissolves the rust. He said you can buy bulk citric acid at farm supply stores. I bet if you looked on You Tube you could find someone using it. Plus when I had stuck parts I would tap the arts with a wood block of big soft blow hammer to get it to vibrate. On a few super tight over arms on K&T mills I would hand a rope from the ceiling and tie it to the middle of a 6 x6 x 10' long and make what could be called a battering ram. Had to wear gloves... good luck
 
TomKro said:
I've been thinking about how to rig up a bottle jack, but I don't have any heavy steel handy. Been trying to figure out how to restrain the base so that I don't damage the casting.

Easy with the hammer - got it.

I tried some heat cycles on the bar without any luck yet (small propane torch), but some heat on the outside of the upper casting is a better idea. With my junk collection in the garage and all the penetrating oil I think best to roll the dolly outside before I give the heater a try.

Thanks for the ideas.
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forget this, just saw the #12 above, that casting is too big
If it's what I think, heating the bar would be counter to what you want. The part holding the bar needs to expand, not the bar. The expansion of the clamping part will break rust, and expand the clamp.
If heating the clamp doesn't work.

This might work:

pick up some angle iron and build a press around the piece. bolt it together. press it apart with a bottle jack. Keep the angle as short as possible were it goes around the bar. length is no an issue, but at 90 degrees it should be as short as possible.

That's my idea. might be practical, might not be. good luck.
 
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In my view, the first step is to free up the split-cotter locks. You can tell if the back half is free if you can rotate the bolt out one turn, then tap on the end of the bolt and have much less that one turn turn of slack left on the bolt. I don't know of any way to free up the front half without something like the blind bearing puller that I suggested.
 
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