china cylinder took death like a champ.

[thompsoncustom]

well did a little bit more work on the cylinder. got the exhaust floor lowered and the sides widened to .050 not sure if I will go any wider as it wouldn't take much to mess it up.

Resbond came in today so I got that in there drying now. put some in the exhaust port and some in the combustion chamber. I just covered the decomp hole and the hole I drilled that way it's close to stock shape but I can test the resbond to see if it holds up.

for the exhaust port I raised it enough to remove the bevel then I put a peice of clear tape inside the cylinder and put a couple rings behind it to hold its shape like this.



says 24 to 48 hours to dry or you can bake at 250 for 1 hour but it can cause it to blister. I will wait 2 days then bake it after that to make sure it's 100% cured.

 

[thompsoncustom]

Here's an update.

took the tape off and found this nice void today.



so I removed all the resbond at this point as that was not going to work. resbond was not fully cured and came out easy.

tired doing this again but the fast way by heating it at 150 for an hr and 250 for an hr.

didn't work ended up bubbling in the port and there was air pockets on the cylinder/tape side.

learned a couple things so far, slow is the way to go I'll try it again and let it sit for 2 or more days and than heat it in the over at 150 for a couple hrs.

stuff doesn't bond to well before it's fully cured but once cured it is much harder and bonded to the aluminum much better.

not sure if it's going to work at this point but I'll play around with it. will contact the manufacturer and see if they have any tips.

 

[Powerstroke Cowboy]

How rough are you making the surface to be bonded to?

The rougher the better I would think.

Interesting project you have going. How much heat can the resbond take?

 

[thompsoncustom]

How rough are you making the surface to be bonded to?

The rougher the better I would think.

Interesting project you have going. How much heat can the resbond take?

80 grit, like you said the rougher the better. It is interesting for sure not saying it will end up making a good saw or have any use in one but there only really one way to find out.

Resbond says it's constant usable range is -300F to 2300F so heat it's a issue. I think the problem I'm seeing with trying to heat it in the oven is the outside gets hard and there in still moisture inside trying to make it's way out.

 

[thompsoncustom]

Little update:

Cylinder sat for 5 days now so I heated it in the oven at 200 degrees for an hour and it didn't warp or bubble anywhere which is good. Downside is there is still voids in it one is exactly the same spot as in the picture above and the sided of the port had voids Im thinking the outside hardens before all the air can work it's way out. Instead of removing it all I just removed the weak areas and filled it back in with more ceramic material.

This is what the exhaust port looks like currently sitting at 112 degrees with no bevel on the inside of the port.



Will heat the cylinder again in a couple days and see how all the resbond looks and if it's all good will clean up the port and try to end up at 110 degrees before I start it. The resbond once fully cured seems nice and hard so I don't think it will have any issues with the heat or gas cutting the only thing the worries me is where the resbond meets the exhaust roof in the cylinder if the ring hooks in behind it even a little I don't know if it will hold on or not even tho the resbond does seem to bond well to the aluminum. Will do my best to buff it with some scotch brite/sand paper before running it.

 

[Ketchup]

With JB Weld heating it up to around 100f makes it flow a lot better so you get fewer voids. No idea if that would help with Resbond application.

 

[thompsoncustom]

With JB Weld heating it up to around 100f makes it flow a lot better so you get fewer voids. No idea if that would help with Resbond application.

thanks for tip I will try that on the next saw if this one lives. bought another 2375 wildthing the other day for 5 bucks so I'll have to get wild with that one as theres no money invested.

 

[thompsoncustom]

well it's game over.

ended up at 109 exhaust and the ring didn't seem to caught at all so I threw it together tonight. could tell it was revving higher than I thought it would be able to.

pulled the exhaust and.....


will have to see if it stayed in the chamber area or not.

 

[Powerstroke Cowboy]

That's a bummer.

 

[Ketchup]

well it's game over.

ended up at 109 exhaust and the ring didn't seem to caught at all so I threw it together tonight. could tell it was revving higher than I thought it would be able to.

pulled the exhaust and.....
View attachment 385092

will have to see if it stayed in the chamber area or not.

Might not be any damage.

How are you prepping the port before epoxy? In his video, Tree Monkey says to just rough the surface with a dry burr and blow it off with air. NO BRAKE CLEANER. Works well with JB.

 

[thompsoncustom]

Might not be any damage.

How are you prepping the port before epoxy? In his video, Tree Monkey says to just rough the surface with a dry burr and blow it off with air. NO BRAKE CLEANER. Works well with JB.

I don't think there will be any damage but I didn't look when I got it off. I did look at the combustion chamber tho and it was delaminating from there as well I just don't think this stuff bonds all that well if it did I think it would be able to take the heat.

I used a dry burr and then 80 grit sandpaper. I always wondered how JB weld would hold up inside the combustion chamber and exhaust port seems like the perfect cylinder to test it out on. I assume it will burn but will do a better job staying in place than the resbond did.

 

[Ketchup]

I don't think there will be any damage but I didn't look when I got it off. I did look at the combustion chamber tho and it was delaminating from there as well I just don't think this stuff bonds all that well if it did I think it would be able to take the heat.

I used a dry burr and then 80 grit sandpaper. I always wondered how JB weld would hold up inside the combustion chamber and exhaust port seems like the perfect cylinder to test it out on. I assume it will burn but will do a better job staying in place than the resbond did.

Maybe JB mixed with Aluminum dust? I have a feeling it will deform at exhaust temperatures, but you might as well continue the experiment.

Is the Resbond hard and brittle? Would it hold up in a transfer tunnel? Does it dull your burrs?

 

[thompsoncustom]

Maybe JB mixed with Aluminum dust? I have a feeling it will deform at exhaust temperatures, but you might as well continue the experiment.

Is the Resbond hard and brittle? Would it hold up in a transfer tunnel? Does it dull your burrs?

ya idk jb weld is just not rated for that temp but does do a good job bonding I wonder how well jb weld would mix with resbond or if I could use the resbond as more of a top coat to protect it from burning.

I'll play around with the resbond peices and let you know i wanted to take a torch to it anyways. I don't know why it won't work in the tunnels as long as it stays bonded to the aluminum gas isnt suppost to affect it. seems to grind easy alot like jb weld would.

 

[thompsoncustom]

@Ketchup

Played with the pieces of resbond that came out of the exhaust port. There are very hard and brittle but not brittle enough to be a problem in the exhaust port I don't think. Not sure if it would work in the head area as it might crack under pressure but that doesn't seem to be a issue currently the main issue is it bonding with the aluminum. In the exhaust port the resbond lifted cleanly off the aluminum if I had to guess how it failed I would say because it didn't bond well to the aluminum the exhaust gases got inbetween the resbond and the top of the port and popped it right off.

Now I hit the resbond with a torch and it does amazing well with the heat I had it glowing red for a little bit and all it did was bubble the surface a little, breaking that piece apart afterwards it seemed to have the same strength as before heating.

I currently have two jb weld/ Resbond mixes drying one is a 50%50 mix which isn't going to work as they don't seem to play well together it became more putty like and looks like it's not going to bond well to anything. The other one is jb weld with a resbond top coat to early to tell how that's going to work out.

 

[thompsoncustom]

The next test run after it dries.



Ground out the chamber then coated it with jb weld and covered that with resbond. Not sure if this will work or not but shows potential from test piece. The resbond when baked forces the water out which may try to separate it from the jb weld. If that is the case and the cylinder is still good after the test run I will probably try it again but I'll dry out and grind the resbond into dust and cover the jb weld with resbond dust for protection. Didn't do anything to the exhaust port at this time.

 

[thompsoncustom]

Well here's the latest attempt ended up putting it in the exhaust too figured I might as well try both at once. I will say it started and run better than I thought it might rpms were still pretty high so I took the exhaust off and everything was holding. Did some cutting with it and it was cutting through the log like butter with the bar buried till I pulled it out and let off the trigger and it died. I could tell it was trying to seize or something was wrong so I stopped there. Here's what happened.



Exhaust is deformed the jbweld under the resbond seemed to swell in the exhaust and as you can see from the piston it didn't hold in the chamber.



The cylinder itself could still be saved as there as no vertical lines that can be felt and there is just a little aluminum transfer right above the exhaust port but I think I've had enough playing with this better to just have the cylinder milled down as far as you can and call it good.

 

[Ketchup]

This is what china jugs are made for.

 

[thompsoncustom]

This is what china jugs are made for.

Indeed. I'm surprised the cylinder held up through all of this.

 

[Ketchup]

I don’t think JB usually does much damage but I’m impressed the digested aluminum or Resbond didn’t wreck it. It’s too bad the castings need so much work to get power.

On 260, I’m very interested in making a divider inside the transfer to create a quad port. Resbond might be the ticket.

Also, I wonder if you made another aluminum (or steel) plug for the chamber but sealed it with Resbond instead of JB…

And there are other epoxies out there…

 

[thompsoncustom]

I don’t think JB usually does much damage but I’m impressed the digested aluminum or Resbond didn’t wreck it. It’s too bad the castings need so much work to get power.

On 260, I’m very interested in making a divider inside the transfer to create a quad port. Resbond might be the ticket.

Also, I wonder if you made another aluminum (or steel) plug for the chamber but sealed it with Resbond instead of JB…

And there are other epoxies out there…

pm me your address I'll send ya some. if you can figure out how to make the resbond adhere well to the aluminum I think it would work well anywhere on the cylinder.