I found a crack in an odd place while pressure testing

[GB SISSON]

Fordestes, I love that kind of solution. Mechanical but with the twist of the suction I really understand that it would work. I have seen way too many jb weld and marine tex repairs that didn't hold up due to poor prep work. If your vacuum could pull a blob into and just past the crack it would be a great repair for pressure pushing out. Gonna find me some belzona 1111!

[Yoyodyne]

Originally Posted by Fordestes

hope this helps.

Thanks, great idea! I can use a vacuum pump.

[Yoyodyne]

Originally Posted by GB SISSON

Gonna find me some belzona 1111!

If you find a source of small quantities, please share. I found 1 KG for $400.

[Tim Ayers]

Originally Posted by Yoyodyne

If you find a source of small quantities, please share. I found 1 KG for $400.

Yes, expensive. 1111 is not sold in small quantities any longer. This is why I used 1212. Sold in smaller quantities and designed to be used for metal that is not surgical clean.

My advise would be to call Belzona. They have local field reps that work your area. In the mean time, send me a message. I have an offer for you.

[glennpm]

I'm a fan of JB Weld but have also used Blue Magic Extreme. Both have very high temperature products. I used the Blue Magic QuikSteel Extreme on pin holes in an exhaust header a couple of years ago and the repair is still fine.

We used Belzona in the power plants I've worked on. It makes sound permanent repairs.

https://www.oreillyauto.com/detail/b.../37901/4388157

https://www.quiksteel.com/brands/QuikSteel.html



Get the surface very clean. I would use acetone for the final cleaning.

[Fordestes]

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Check with your local welding shop , we found a cold weld compound at a welding supply, we had a Dozer with a cracked radiator tube, I used the same process to repair the damaged tube and within 24 hours it was and still is running , the labor to repair the machine was over $5000 ,the construction company had a deadline and a week of down time was out of the question . I have used regular J.B. Weld in a high heat area without issues, I wont use J.B quick for a high heat area, I personally would try the regular J.B. weld in your case, I have used regular J.B to repair a damaged 3208 Caterpillar block deck at the fire ring area ,the repair lasted me over 6 months while being driven700 plus miles in a week till the new replacement truck arrived, I Designed an injection tool to force the compound into the crack and then built up the deck surface around the top of the cylinder fire ring area, I have used Marinetex on lower water jacket cracks (low heat area) and none have failed. Mabe you can find a sample size from the manufacture or a dealer, check with a caterpillar dealership ,some mechanic may have a bit left over from a previous repair ?

[glennpm]

Yes good point on not using the J-B Weld Kwik version. It has poorer properties than the "regular"


From https://www.jbweld.com/product/j-b-weld-twin-tube


"J-B Weld™ is The Original Cold Weld two-part epoxy system that provides strong, lasting repairs to metal and multiple surfaces. Mixed at a ratio of 1:1, it forms a permanent bond and can be shaped, tapped, filed, sanded and drilled after curing. At room temperature, J-B Weld™ sets in 4-6 hours to a dark grey color. A full cure is reached in 15-24 hours. J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured."


For a vertical surface like yours, you will want to dam the J-B to keep it where you want. It helps to let it setup for a little while before putting the final coat on. For vacuum or injection in the crack, apply it right away.


I find that blue masking tape is good for the dam. You can also keep moving it up with a pop-sickle like stick for a few hours after you apply it. check it every fifteen minutes or so.

[Fordestes]

It looks like the engine is on the stand , so tilting it horizontal as I stated above would be the best.as the compound is vacuumed in you should see a pattern of the crack slowly sinking into the cracked area, that indicates it is working and allows you to see what portion is being treated, remember to smear a little over the area after the vac. is removed and make sure it does not keep seeping in during the cure time as to avoid a pin hole in the crack surface. I had it seep overnight and had to redo a small area, that was a large cracked though.