Bandsaw table crack

[Bernie Kopfer]

Couple of years ago I obtained a used 14" Jet bandsaw. After tuning and pimping it up it has proven to be a excellent 2nd BS and sees limited usage.I noticed when I got it what appeared to be a one inch scratch that on closer examination proved to be a small hairline crack in the table from one side of the blade slot. Barely detectable to the fingernail. Now for some reason that crack has tripled in length on one side and started on the other side of the slot but still remains barely detectable.
It does not affect the performance of the saw but I would like it to not get longer. I always keep the blade slot alignment pin in place. Any suggestions on what to do short of replacing the table?

[Bill Dufour]

Drill a small hole at the end of the crack so it will not grow. Do this at both ends that are in. the field of the table not where it already ends at the blade hole.
Then think about jb weld etc. Personally I would drill the crack ends then attach a 1/4 steel sheet on top screwed down to hold it together.
Welding/brazing/soldering risk warping or causing stresses leading to more cracking.
Bill D

[Richard Coers]

Bill has it right. The only other suggestion is how hard do you install that tapered pin in the blade slot? Just barely push it in, definitely no tapping with a hammer!

[Erik Loza]

+1 for drilling a hole, then filling crack with JB Weld. Just make sure there is ZERO wax/oil/moisture in the crack area or you will get no adhesion. I reccommend irrigating thoroughly with automotive brake cleaner then blasting dry w/ compressed air. Best of luck with it.

Erik

[Bill Dufour]

Then I would wait a day before saying it is dry enough to jb weld it.
Bill D

[John K Jordan]

+...I reccommend irrigating thoroughly with automotive brake cleaner then blasting dry w/ compressed air. Best of luck with it.

Great degreaser. I buy it by the case.

[Bernie Kopfer]

I’ll try the hole drilling idea to stop the crack from growing. Should the hole go all the way through the table? The crack is barely detectable with a fingernail so there is nothing to fill with JB Weld. The blade slot pin is put in finger tight only. Hope I don’t have to go looking for a replacement table!

[Alex Zeller]

It's up to you to figure out if it's worth doing but what I would do is get a dye penetrant kit and test the backside of the table to see if it goes all the way through. Chances are it does. But if it doesn't then I would remove the crack with a grinder going just deep enough to remove it and then fill it with epoxy. If it does go all the way through it'll show you exacly where the end of the crack is. Drilling a hole will do no good if you don't do it at the end of the crack. Have you looked on ebay to see if you can find a replacement table? It might be the easier route.

[Bill Dufour]

Yes, drill all the way through. use the smallest bit you are comfortable with. Say 1/8" or so. no need for any larger as long as the entire crack is touching the hole, or will be, if it gets a fraction longer at any depth.
Bill D

[John K Jordan]

… what I would do is get a dye penetrant kit …

Excellent advice. The crack may have advanced beyond what’s visible. The dye will show exactly the extent of the crack including the exact end if drilling a stop hole. One thing, the due penetrant test may not be as useful on the bottom if the casting is rough (could be difficult to clean off the surface dye before spraying on the developer) but it should work well on the typically smooth table surface unless the cast iron is excessively porous.

I wonder if annealing the table would relieve internal stresses and stop the crack. But it might then need to be reground if it warped. I like the table replacement idea.

JKJ (NDT inspector many decades ago)

[William Hodge]

This sounds like something to deal with effectively, sooner than later.
I have never before thought about what would happen if the band saw table just broke in half and fell on the floor while I was using it.

If it were mine, I would take tit to a local machine shop, and have them fix it. I have done this before, people know how to repair cracked castings. They heat the whle thing up, do some type of brazing, and cool it off slowly. They then machine as needed. I repaired a shaper insides and a Maka mortise main casting like this.

Another route is to buy a new table.

Patching with plastic glue is something you could run by a machinist that has experience with cast iron repair. Perhaps it's adequate.

[Greg Quenneville]

The JB Weld would just be to restore the surface of the table, not to add strength.
On a previous drill press resurrection project I had to epoxy up the arc of shame line of drill craters. I used a stiff mixture of epoxy and cast iron dust which dried hard and was a durable repair still in daily use 12 years later.

I got the cast iron dust from a Midas brake shop. I don’t know if anyone still machines brake discs?

[John K Jordan]

... I used a stiff mixture of epoxy and cast iron dust which dried hard and was a durable repair still in daily use 12 years later.
I got the cast iron dust from a Midas brake shop. I don’t know if anyone still machines brake discs?

An angle grinder and a piece of cast iron should make some dust.

I thought JB Weld was basically a high temperature epoxy with some type of fine iron particles.

I once used it to secure a small strong cylindrical magnet into a hole drilled in a steel tool that holds fence staples while hammering. I wanted the magnet to hold the staple in the slot in the tool. About 1/2 of the magnet sticks up out of the hole. After applying to the inside of the hole and as a fillet around the magnet I watched the JB Weld magically rise up from fillet and form a dome over the magnet. I kept pushing it back down until it started setting up!

I have used JB Weld here on the farm to repair and modify things made of metals and some plastics (it sticks to some plastics better than others), often on dissimilar materials. I don’t use it on something that could be better repaired with welding, brazing, or mechanical fasteners. I usually buy the the large size (10oz I think.)

I can’t imagine it being useful on a hairline crack in cast iron, except perhaps as a hole filler. Before I got tools rests for my lathes with hardened steel top bars I used it for years to fill small voids in the working surface of cast iron stock rests. Worked well and held up to heavy use.

JKJ

[Frank Pratt]

According to crafty review, The reason it cracks is the feed is too fast, so the dull tooth has to work too hard to cut the wood and it bends the tooth back and cracks it in the weakest point, the bottom of the gullet. Most of the time it is something that simple.

It's the table that's cracked, not the blade.

[Frank Pratt]

If you go the epoxy route, I would not use anything like JB Weld, just because it's too thick to penetrate the crack. Use a low viscosity slow setting epoxy and warm the cast iron to well above body temp, but not too hot to hold your hand on. Then pour on the epoxy. Use a shop vac hose on the bottom side to suck the glue into the crack.

I believe that, along with drilling a hole at the end of the crack will provide a long lasting fix.