Broken case repair demo

I bought a 066 RL to rebuild that had the case broken off near the serial number, such that you could not bolt on a spike. I drilled and tapped 6x32 stainless screws into the case and formed up the area. I used the new spike, covered in blue masking tape as part of the form. I cast it with the bolt in it, also covered with tape. The entire area was sandblasted and cleaned with lacquer thinner prior to applying the JB Weld. This area is full of structural webbing. So with the JB Weld interlocking in all these pockets, in addition to the stainless screws, this repair should be very strong. What would you have done different?





Made good use of the old 084 badge.




Bolt still in it.


The spike removed.


A couple small air pockets got trapped behind the spike.

Not only is the bolt holding the spike, but with the JB Weld cast around the spike, the entire outline of the spike is spreading the stress over a much larger area.

Nice

What a great job you did there bro... Maybe I'da drilled some anchors in the case to stick in the jb Weld like Rebar??? I dunno, you did a pretty damned fine job there bro. Think it'll hold?? It shore does look nice and professional...

eh?

ciscoguy01 said:

Maybe I'da drilled some anchors in the case to stick in the jb Weld like Rebar???

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I did. There are 2 stainless 6x32 screws in there, drilled and tapped and then Loctited into the case.

Ahhhh

you my friend have got a gift... hehehehehehehe..

eh?

That looks great! Give us a report back after you have used it some. JB Weld is starting to replace duct tape as my go-to bandaid, but you sir have perfected the art.
Dok

Good Post brad, wish we could have seen the pics of the screws/rebar.

Is that case split????? it had good bearings in it.....lol

You don't mess around do you. It's been, what a week and you got them stripped down and moving right along.

Brad, I think you did a hell of a job on that case repair. You should send those pics to the J-B Weld Co. They might send you a couple more tubes on the house.

Freakingstang said:

You don't mess around do you. It's been, what a week and you got them stripped down and moving right along.

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I think Kevin (cut4fun) created a "monster"!

Good job!

What would I do differently? If you look at a similar repair in my 056M2 rebuild thread - I like to put a metal insert in the hole with fender washers on both side to act as a buffer from the JB. i.e. the metal takes the bolt pressure (high), not the JB. A small washer in the hole and the sleeve for the bolt is more important than the back side. No idea if it works better than yours, but it's standing the test of time in the hands of a guy that's using the ???? out of the saw!


Post 102, 103 etc..

http://www.arboristsite.com/showthread.php?t=48040

omg

Lakeside53 said:

Good job!

What would I do differently? If you look at a similar repair in my 056M2 rebuild thread - I like to put a metal insert in the hole with fender washers on both side to act as a buffer from the JB. i.e. the metal takes the bolt pressure (high), not the JB. A small washer in the hole and the sleeve for the bolt is more important than the back side. No idea if it works better than yours, but it's standing the test of time in the hands of a guy that's using the ???? out of the saw!


Post 102, 103 etc..

http://www.arboristsite.com/showthread.php?t=48040

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That's a beautiful yard you have there dude. Only thing missing is a hammock... heheheheheheh

Lakeside53 said:

I like to put a metal insert in the hole with fender washers on both side to act as a buffer from the JB.

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I knew you had done a repair similiar to this. I should have gone back and looked at it. I would have done the washer thing had I thought of it. Good idea.

Freakingstang said:

Good Post brad, wish we could have seen the pics of the screws/rebar.

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I realized that when I was processing the pictures. Too late now

Is that case split????? it had good bearings in it.....lol

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Yes, I split them. I had the whole gasket kit, so why not. It was easier to get all the old oil varnish out of the bearings and make sure everything was clean this way.

You don't mess around do you. It's been, what a week and you got them stripped down and moving right along.

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With any luck, this saw will be running Saturday or Monday, since I'm off Monday. The 084 is finished except for the plastic covers. The other parts 084? Well, it's not a saw anymore It lost what few good parts it did have to the "new" 084. About all that's left is the bare case halves, the flywheel, and the oiler.

broken case repair

blsnelling, excellent job, looks as if you might have some molding experience!Something I use in addition to JB is fiberglass mat, it gives it more structural strength acting as a frame or skeleton.The type of mat I am refering to is used in automotive and marine applications.

Nice work as always Brad

Fender washers on the faces is a good idea. How are the screws held in.Loctite JB weld. Sand blasting gives a good tooth to imbedded screws, surface area you know, fill the screw heads as you start, air is a pain. Vibrate the peice if you can, air again. Have you ever tried Defcon, thew Titanium is the meanest, I use it to bed largee rifles, heck any rifle but it takes shock very well. Jmh

What would I have done differently?

I don't know if there would have been enough clearance, but I would have thought about fabricating a custom spike with longer ears to try and get it bolted to the case's remaining metal vs. the epoxy. Or maybe the ear could have been extended by brazing on a short strap to extend it. That way it's fastened to metal but is supported by both metal and epoxy.

It looks like the top corner had some existing case metal if the ear was a little longer. I can't tell if the bottom did.

Nice job!!

davefr said:

...I would have thought about fabricating a custom spike with longer ears to try and get it bolted to the case's remaining metal vs. the epoxy. Or maybe the ear could have been extended by brazing on a short strap to extend it. That way it's fastened to metal but is supported by both metal and epoxy.

It looks like the top corner had some existing case metal if the ear was a little longer.

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Great idea. If you noticed there's already another hole through the remaining case there. It's a strong reinforced hole to boot. I could weld a strap of steel to the spike and bolt it into this hole as well. The only issue I'd have to deal with is that the stainless screws I installed go through that hole. I'd have to drill them out. It may be a little difficult to do that and not have the bit walk out into the Magnesium. I may give that a try if I decide it needs the additional support. What do you guys think? Necessary? All the stress will be pushing back against the spike, rather than pulling. The entire spine of the spike is supported by the new casting. I don't really see it going any where.

blsnelling said:

Great idea. If you noticed there's already another hole through the remaining case there. It's a strong reinforced hole to boot. I could weld a strap of steel to the spike and bolt it into this hole as well. The only issue I'd have to deal with is that the stainless screws I installed go through that hole. I'd have to drill them out. It may be a little difficult to do that and not have the bit walk out into the Magnesium. I may give that a try if I decide it needs the additional support. What do you guys think? Necessary? All the stress will be pushing back against the spike, rather than pulling. The entire spine of the spike is supported by the new casting. I don't really see it going any where.

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I wouldn't redo anything. Just cut some wood and see how it holds up. The normal stress on the spike will be tension and compression and it should hold up fine. The weakness will be lateral or twisting force but I don't see how that would come into play in normal cutting.

I tend to think these things break off more from being thrown around in the back of trucks vs. cutting.

davefr said:

The normal stress on the spike will be tension and compression and it should hold up fine.

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Should be compression only. That's why I'm not inclined to add the stap. Never the less, it's a great idea that would definately make it stronger.

I agree with Dave... The forces are both compression, tension and twisting... and high/low frequency pulses and (vibration) from chain action.

Lot's of forces on the dogs when cutting in big wood - not just just you pushing and the wood pulling.

I'd just try it. JB is amazingly strong.