broken press part
Oh, I hope someone can help me out here. I have a Sigwalt #5 and a critical cast iron piece has broken. I noticed (a bit too late) a discussion earlier about the pin in the back of the Sigwalt that moves and loosens itself and it seems that is what has happened to me. Something caused the same area to break last week, I found someone who felt confident that they could mend the piece as well as could be done, but couldn’t guarantee it wouldn’t break again and so now, since it’s broken at the mend I’m feeling that a repair probably won’t be the solution. So, in short, I’m wondering if there is anyone that might be able to reproduce these parts out there? I really love this press and don’t want to give up on it.
If you could post a picture of the broken part it would be easier to visualize how difficult or effective the repair would be. I have gone to the extent of having several broken pieces made by a local foundry in iron. This can be expensive, particularly since newly cast parts nearly alway require a bit of machining.
Don’t give up on the problem. As long as you can be patient any breakage can be solved by one means or another.
Looking for your picture …
Jim Rimmer
Here are a few images of the wreckage. You can see the previous mend and the break is just below the seam. This is why I’m concerned about trying to rejoin the pieces. It could be that it may have held, if the pin hadn’t slipped, causing strain to that side of the hinge again. Can’t be sure.
I feel confident that the metalsmith who did the work on the piece knows what he’s doing. I just wonder if it’s worth trying again, he knows the metal but is not familiar w/ presses.
Thanks for looking.
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If it’s a pin coming loose and moving, putting all the stress unequally on side only, you need to figure out how to avoid that problem in the future. Otherwise, just as you’re thinking, the break will happen yet again, whether on your repaired part or on a replacement or reproduction part. In short, from your description the problem isn’t with your broken part (which can be repaired again) but with the part which is causing this one to break.
You’re right. The forum that mentioned this problem earlier on the same type of press said the solution is to put a notch in the pin, causing a slight expansion which would help create a tighter fit for the pin. I’m going to try this solution.
So, do you think I should just have this piece mended again?
Ask you welder who made the repair the first time if he can put some dowels into the piece to strengthen it if he can repair it again. I’m thinking he may not be able to weld to what’s already been welded.
That photo shows the classic break indicative of an incorrectly prepared weld. There are many names for that particular break - some printable, most not - but ‘shock’ weld comes to mind. That is, the only part brought to heat - and that by the welding current itself - is the weld scar which remains on the re-broken piece. Examining the fresh break will reveal high concentrate of surface carbon that will support my suspicions.
Your best course of action is to find replacement piece and, as DR suggested, remedy the underlying cause before using the press.
That said, the piece is recoverable. As Lammy suggested, pinning the pieces is a first step; after proper grinding to establish sufficient bevel to provide weld surface. Then the entire piece must be pre-heated prior to making first pass with the rod. After that first pass, allow the piece to normalize (controlled cooling) and then re-clean the entire weld. Again, re-heat, weld, normalize. Repeat procedure until sufficient metal has been replaced. Any knowledgeable welder knows the steps involved. Of course, it does take time. And time is money. But there’s no excuse for that weld to have failed in that manner.
All the information from “Forme” is stuff that I have seen done by the mobile welder who has come to my shop a few times to fix things on site, like the back end of the Colts (since I didn’t want to move the entire press to his shop).
Along with the slow cooling, he tapped on the piece with a pointed hammer as the piece cooled. He explained that it helped to align the molecules, if that’s the correct word he used. Apparently that helps to make the weld and the surrounding metal stronger.
I had a break very much like that about 35 years ago on my old bench top Columbian platen. The welder added strapping around the hole and the top and bottom. The bandage was pinned at each end, and brazing floated into every nook and cranny. The strapping was 1/4” steel. If you have room that the strapping won’t bind as the platen moves you might try that remedy. I think the strapping could be as thin as 3/16” or even1/8” but a welder could tell you more about that.
As has been mentioned previously here, it is necessary that the pin needs to be properly cotteripinned so that it doesn’t work loose and put all the stress on the broken side again.
Also when the welding is being done, you need to have something in place to assure that the holes are aligned and not running at a slight angle to cause the pin to bind. A good welder will know that, but you should make sure that is done.
Best of luck with it.
Jim
Thanks for all the information. So glad to have the benefit of your combined experience to help me out here. I’ll talk w/ the welder about the possibility of pinning and/or reinforcing the piece. I’m pretty sure he did the annealing process throughout the repair, as he described the way he would go about it to me. I’ll also see what I can do about this pin traveling. The forum which discussed this before (which I can’t seem to find again) mentioned putting a notch in the pin right around where this second hinge is to expand that end a bit so it won’t slide so easily. Has anyone else tried this? Is it advisable?