Topic: Best way to fix chip / crack in case?

[bunghole]

Take a look at this:



This is the bottom of the timing cover.  As you can see, there is a damaged (to say the least) thread hole.  Part has chipped off and there is are two cracks, one on either side of the hole in the circular part of the housing that run about 1 centimeter back.  What would be your recommendations on fixing this?  I was thinking of JB welding the whole area and then retapping or helicoiling it.

[gary-stidham]

if you can scrue the bolt back in with anti seas or Teflon then mold the jb weld on this will make it so the threads are still their with no problems when hard unscrew the bolt and sand end flush

[GammaFlat]

I have used JBWeld on the block and engine cover of Yamaha Razz scooters.   

Get your area super clean.  I used layers of duct tape to make the "cast".  I let gravity (top) form the areas that needed to be flat - laying your bike on it's side might not be feasible .  I needed to form around a bolt hole in a cover and I used a cheap pen to maintain the hole - I figured that in the worst case, I could drill out the plastic pen - as it turns out I was able to wiggle it out.  I didn't need to recreate threads as it looks like you'll need to.  I did do some filing to flatten the sealing surfaces - which was a breeze.  It was shocking how nice it came out.  No leaks and seems strong although I don't know how it would work if you're tapping threads and putting any torque on the stuff. 

Great idear Gary!

[oldbiker]

A top job could be done by supercleaning and then building up with 'Lumiweld'  This is a form of aluminium solder which can be run using a Butane torch. It's melting point is well below the melting point of the casting but it is at least as strong as the base material. Then the hole can be drilled and retapped. I've used it myself on an aluminium bracket and I've seen a demonstration where a joint was made and then tested to destruction. The parent metal failed before the Lumiweld.

[bunghole]

Is it as strong as the white Elmers Glue I was gonna use?

Just kidding.  Lumiweld.  I'll look it up.  Thanks!

[bunghole]

A top job could be done by supercleaning and then building up with 'Lumiweld'  This is a form of aluminium solder which can be run using a Butane torch. It's melting point is well below the melting point of the casting but it is at least as strong as the base material. Then the hole can be drilled and retapped. I've used it myself on an aluminium bracket and I've seen a demonstration where a joint was made and then tested to destruction. The parent metal failed before the Lumiweld.

You think this is the same thing?  Sounds like it:  http://www.eastwoodco.com/jump.jsp?itemID=1222&itemType=PRODUCT

[eldar]

Another option is a 2 part epoxy that is a solid, not a semi-liquid like jb. You can get it at walmart and once it dries, it is very strong. Certainly not lumiweld though.

[BobbyR]

A top job could be done by supercleaning and then building up with 'Lumiweld'  This is a form of aluminium solder which can be run using a Butane torch. It's melting point is well below the melting point of the casting but it is at least as strong as the base material. Then the hole can be drilled and retapped. I've used it myself on an aluminium bracket and I've seen a demonstration where a joint was made and then tested to destruction. The parent metal failed before the Lumiweld.

You think this is the same thing?  Sounds like it:  http://www.eastwoodco.com/jump.jsp?itemID=1222&itemType=PRODUCT

Actually you can get it at Home Depot. Bernz O Matic makes it or packages it. Pretty cheap since you only have like 4 sticks in a bag.

[oldbiker]

Bung and Bobby, I believe those products are the same thing. Once one company comes up with a solution, others soon join in. I do notice that the Lumiweld supplies 4 or 5 sticks with an outfit while the Eastwood seems to have 30 sticks with their outfit.
Its great for building up broken fins which can then be filed until you cannot tell they were broken in the first place.

[bunghole]

I bought some of the BernzOMatic version yesterday and tinkered around on a junk head, but I couldn't get it to stick to the  head.  Maybe I need to clean the area more.  Also, on the Eastwood site (I think), there is some mention of dipping some stainless into the puddle of molten aluminum.  Anyone have any info on what that is all about?

Anyone have any tips on using the stuff?  I've got a few small chips in my cylinder and head and would love to be able to fix them.

Thanks!

[lordmoonpie]

Or ou can send it to JME Engineering in Coningsby Lincolnshire England - he can fix anything like new including rebuilding broken cylinder fins up so that you can't tell they were ever smashed off. Good prices - just a shame he's on the wrong side of the pond for you guys :-)

[oldbiker]

Bunghole, the base material MUST be super clean with no trace of oil etc. The stainless steel scraper is used to dip into the molten puddle and scratch the surface of the the parent below the puddle to break the oxide layer. Once the oxide is broken the Lumiweld flows under the oxide and adheres to the parent.