Another crack thread

Rennie, there "MIGHT" be a fix, (at least a temporary one) while you're saving for a new one. If you would "First" drill a hole at the end of the crack with about a 3/16" bit (to keep it from cracking further), then:
1. Drill a 1/4" hole on each side of the crack about 1/4 of the distance up from the bottom edge in the picture and tap the holes for a high strength 1/4" machine cap screw.
2. Cut two 1" lengths of small angle iron and drill a hole in each side of each angle that will accept a 1/4" dia bolt.
3. Use the cap screws and install one piece of the angle on each side of the crack using the holes you drilled previously.
4. Insert a 1/4" bolt through both of the pieces of angle that are sticking out from the jointer piece, and put on a washer and nut and tighten. This should pull the crack together, AND if the crack is pulled together, it "MAY" flatten out the casting and remove that .005 sag you have in it now. At least, it would keep it from Flexing while in use.

5. Optional: Loosen the bolt that pulls the crack together and blow some solvent through the crack and blow it dry. Then, force some "JB Weld" into the crack (using a vacuum cleaner on one side to help pull the JB Weld into the crack), then retighten the bolt to pull the crack back together and let it set over night. If it works, I would leave the clamping device, (angle brackets & bolt), in place IF it doesn't interfere with the operation of the machine.

I hope it works out for you if you want to try it.

I drilled the 3/16" hole at the top of the crack to keep it from moving up. I also loosened the way screws and tried closing it up with a clamp - no go. I don't know how long the crack has been there, but I'm going to have to live with it for a while. I may try removing the table tomorrow and see if I can squeeze it together with a clamp. If I can get it to move then I might follow through with the rest of the fix.

Rennie Heuer said:

I drilled the 3/16" hole at the top of the crack to keep it from moving up. I also loosened the way screws and tried closing it up with a clamp - no go. I don't know how long the crack has been there, but I'm going to have to live with it for a while. I may try removing the table tomorrow and see if I can squeeze it together with a clamp. If I can get it to move then I might follow through with the rest of the fix.

Click to expand...

Sounds like a reasonable plan to me. I'll keep my fingers crossed for you. It sure sounds like there were some internal stresses that developed in it when it cooled from the original casting process.

"IF" this process does NOT work, you could probably still Braze it without trying to pull the crack together and that Would stabilize it, because since it is several years old, I would think that MOST of the stress has relieved itself by now.

To take out the .005 dip, you could then do like I did on on the tables of a 6" Craftsman Jointer that had dips in them. I took a 24" Heavy Cast Aluminum Alloy Mason's Level and pulled a 1" wide strip of Emery cloth tight along one edge and fastened it to the ends of the level, and then used it to hone it until it was flat all over. (It "DID" take a while over a period of time, but it worked). I will admit that you DO have to be really "Inspired" to do this last process.

You can also flatten a piece of steel or iron by using another know flat piece of steel or a section of granite like something left over from a counter top. You might find something like that from an installer. Get some blueing paste and lightly paint it on the granite. You then put the granite down onto the table and move it around, the high spots will take the blueing and you then grind them off with a die grinder. You would need a piece of granite larger than the table. That's pretty big and 2 persons of stout stature would be needed. That and a six pack or so. Of course if you could find an old granite counter top the best way would be to invert the table on that and spot it in that way. I've done 1000's of die steels this way to get them flat after heat treat.

It is also true that you would want to heat up the whole area that needs repair. Any heating of iron introduces stresses that can cause problems down the road. I would also post heat the area after it cools down somewhat in a larger area to help disapate any introduced stresses. 500 degrees is all you should need in post welding heat.

Paul Downes said:

It is also true that you would want to heat up the whole area that needs repair. Any heating of iron introduces stresses that can cause problems down the road. I would also post heat the area after it cools down somewhat in a larger area to help disapate any introduced stresses. 500 degrees is all you should need in post welding heat.

Click to expand...

This is starting to sound like a lot of work!!

Only 500 degrees?!

I appreciate all the advice from everyone, I really do. I'll have to give all this a lot of thought.

Rennie Heuer said:

This is starting to sound like a lot of work!!

Only 500 degrees?!

I appreciate all the advice from everyone, I really do. I'll have to give all this a lot of thought.

Click to expand...

How big is that oven of yours?

There are alot of ways to go at this. I looked up on how to weld cast iron and they gave 3 methods. One was to preheat from 500 to 1200 degrees and to weld it about an in at a time and to let it cool very slowly to minimize stress. The second method was to heat to only about 100 degrees which in Texas you just sit it in the sun for half an hour, than weld no more than an ihch at a time to keep the area from getting to hot. The third method involved drilling and tapping and inserting steel bolts to weld together to weld up the crack, again watching the heat. Sometimes it might be best to leave well enough alone if your not comfortable trying to weld cast iron. I would just try to stabilize it if it were me till I saved enough for another jointer then try to fix it more permanently.

Alan Bienlein said:

Sometimes it might be best to leave well enough alone if your not comfortable trying to weld cast iron. I would just try to stabilize it if it were me till I saved enough for another jointer then try to fix it more permanently.

Click to expand...

I think that for now this will be my course of action. I loosened and shimmed the in-feed table this morning to get it as close as possible (it was just a tad out) and now the only problem is along the center line of the table. For wide boards this should not be a issue and for jointing narrow edges I just need to remember to make sure I'm tight to the fence. The outfeed table is fine so once I pass the 1/3 mark and transfer my weight to the outfeed all should go well.

Someday I'll move up to an 8".

Don't set your sights so low - with all the metalworking experience you'll gain by fixing this one you'll be ready to restore an old 12" beast!

Let us know what you decide to do and how well it works.

What Delta is telling you sounds strange. By the way, I am not a Delta fan and own no Delta equipment and do not plan to own any Delta equipment. Most good jointers are built so you can adjust the infeed and outfeed tables with shims, if necessary, to make them parallel. My Jet jointer manual explains how, if I remember correctly.

The first thing I would do is see if you can find a used jointer the same model. Take the best of the two and make one.

I do not guarantee the following, but I throw it out as a suggestion. Proceed at your own risk.

There is a way to weld cast iron. I am a mechanical engineer, so I have an idea of the process, but no practical experience. My brother in law is a boiler maker, so he knows welding procedures and has the practical experience. We just discussed an issue with a cracked casting we have at the paper mill where I work.

I do not know the cost of this whole process, but it may be cost prohibitive.

First, you have to heat the cast iron piece totally. I cant remember the temperature, but I can find that out for you (I believe it is in the 300 degree range). There are "crayon" sticks that melt at that temperature so you can test the piece and check the temperature all over. This temperature has to remain throughout the welding process and then be evenly cooled slowly. If the piece is going to crack again, it will crack while cooling. Cast iron has to be welded with nickle rod, which is expensive. I agree with everyone here that you need to drill a hole at the end of the crack. The end of the crack is a very high stress concentration point and drilling a hole at the end of the crack acts as a stress relief.

Second, after welding, the table can be flattened with a blanchard grinder. In the paper industry, we have different types of plates that have to be flat within 0.002", so we have them blanchard ground. You would have to look in your area to see what machine shops have blanchard grinding available. It may be best to have both the infeed and outfeed tables flattened together so that they are flattened relative to the same reference. Then when you put the jointer together, the alignment procedure is faster and easier.

This is a risky process - as in life, there are no guarantees. If you do this, please make sure you have enough money set aside to buy a new jointer.