The Official JB Weld Fan Club Thread

[Woodpecker]

@bwalker

@Woodpecker can you make a Captain Crunch batch for science and stuff?

I'm sure I could do that. Anything for science and stuffs. It all ends up looking like this though:

Just dont ask for a devcon version.

 

[andyshine77]

I stopped using Devcon and went back to good old fashioned JB Weld. The Devcon putty is much harder to get into the corners of the intake port.....which makes me wonder if it's also not getting into the divots I drill to help the epoxy bond.

I've used JB Weld in a metric chit ton of intake ports......and have yet to hear about a failure.

But....I don't use it for anything else. Wallowed out threads get inserts, or welded up. Cracked parts get pitched in the trash or welded and powdered.

Anyone wanna buy some unopened Devcon?

Yeah it's a little thicker than JB, I just work it in to make sure it sticks. I normally use a small ball burr to grind dimples the bottom of the port for epoxy to grab on to. I did have to grind out Devcon on a Poulan I ported for a friend, and it filled every divot perfectly, and the Devcon didn't chip or flake off like JB does when it gets thin as you're grinding or sand, that's what sold me on the stuff.

Like I said JB isn't junk though, and I doubt whoever said that has actually used it.

Pretty isn't it lol.

 

[Stump Shot]

View attachment 182685


I'm sure I could do that. Anything for science and stuffs. It all ends up looking like this though:
View attachment 182686
Just dont ask for a devcon version.

Oh yes I did, this is the perfect place for @bwalker to enlighten us about epoxy.

That looks wonderful, love the color.

Don't have to worry about that, I want it to pass through not stick and stay. But if you change your mind I hear @Mastermind has a stash dot dot dot

 

[Basher]

I stopped using Devcon and went back to good old fashioned JB Weld. The Devcon putty is much harder to get into the corners of the intake port.....which makes me wonder if it's also not getting into the divots I drill to help the epoxy bond.

I've used JB Weld in a metric chit ton of intake ports......and have yet to hear about a failure.

But....I don't use it for anything else. Wallowed out threads get inserts, or welded up. Cracked parts get pitched in the trash or welded and powdered.

Anyone wanna buy some unopened Devcon?

There is better types of Devcon for for filling in transfers but its much more JB like in that its slightly runny and needs to be dammed up to prevent it from shifting /flowing from where its needed. We have been using it since the 70`s around the boatyards/marine slips and repair facilities. Type 10710 for aluminum based repair mixed in a 5:1 ratio would repair the busted out side of a crankcase where a rod was thrown, bottom ends of outboards where gears had broken and smashed out through the castings, cylinder blocks that had froze and busted water jackets and so on. The yard used to bring in 30 lb pails of it, we all snuck a bit of it home...LOL

 

[andyshine77]

There is better types of Devcon for for filling in transfers but its much more JB like in that its slightly runny and needs to be dammed up to prevent it from shifting /flowing from where its needed. We have been using it since the 70`s around the boatyards/marine slips and repair facilities. Type 10710 for aluminum based repair mixed in a 5:1 ratio would repair the busted out side of a crankcase where a rod was thrown, bottom ends of outboards where gears had broken and smashed out through the castings, cylinder blocks that had froze and busted water jackets and so on. The yard used to bring in 30 lb pails of it, we all snuck a bit of it home...LOL

Maybe my batch of Devcon is different as I didn't find ti to be all that thick, maybe an old batch will get thick over time.

 

[P.M.P.]

Not to derail the jb talk butt...
This stuff works great I've used it a few times

Just work fast as soon as you stop squeezing it out the mix tube the end hardens. You have to be quick.

 

[Gary Courtney]

What did you use it on Gary?

I tried it on an old table saw. A piece of casting where a bolt hole was broke under the bolt hole. I cleaned the area with brake cleaner and drilled a few 1/16 th. holes and mixed both parts well and applied. It cured for about 7 days before I put motor back on and it felt very solid. After a little usage the weld broke loose. Another instance was on a steel water trough. I preppped the area as well as I knew how and applied and it lasted about 6 months and started leaking ,so I drained tank and noticed a fraction of space between weld and the galvanized so I took my nail and applied a little upward pressure and the whole patch came up. Possible I may not be applying correctly but I thought I took proper steps?

 

[Basher]

Maybe my batch of Devcon is different as I didn't find ti to be all that thick, maybe an old batch will get thick over time.

There is a few different consistency types, some are putty like, some are more mastic like and others almost like molasses. The 10710 is more like molasses, it will run, flow or seep depending on the temps around it when applied but it will get into any pores that are there, the holding power was very strong. One of the ,lead hands, put a busted aluminum crankcase together with it, after curing we all took a turn smashing it apart to check the bond and it worked like welding does, it would break new metal before the Devcon bond would let go.

 

[Basher]

I tried it on an old table saw. A piece of casting where a bolt hole was broke under the bolt hole. I cleaned the area with brake cleaner and drilled a few 1/16 th. holes and mixed both parts well and applied. It cured for about 7 days before I put motor back on and it felt very solid. After a little usage the weld broke loose. Another instance was on a steel water trough. I preppped the area as well as I knew how and applied and it lasted about 6 months and started leaking ,so I drained tank and noticed a fraction of space between weld and the galvanized so I took my nail and applied a little upward pressure and the whole patch came up. Possible I may not be applying correctly but I thought I took proper steps?

It definitely will not bond to galvanized surfaces, galvanize is a tough item to get any bonding to as its a sacrificial material its surface is constantly shedding if that is a term and very little bonding products will adhere to it for long.

 

[MG porting]

I stopped using Devcon and went back to good old fashioned JB Weld. The Devcon putty is much harder to get into the corners of the intake port.....which makes me wonder if it's also not getting into the divots I drill to help the epoxy bond.

I've used JB Weld in a metric chit ton of intake ports......and have yet to hear about a failure.

But....I don't use it for anything else. Wallowed out threads get inserts, or welded up. Cracked parts get pitched in the trash or welded and powdered.

Anyone wanna buy some unopened Devcon?

Lol.if you think it's junk then nope I'll just stick with JB weld.

 

[MG porting]

Yeah it's a little thicker than JB, I just work it in to make sure it sticks. I normally use a small ball burr to grind dimples the bottom of the port for epoxy to grab on to. I did have to grind out Devcon on a Poulan I ported for a friend, and it filled every divot perfectly, and the Devcon didn't chip or flake off like JB does when it gets thin as you're grinding or sand, that's what sold me on the stuff.

Like I said JB isn't junk though, and I doubt whoever said that has actually used it.

Pretty isn't it lol.

View attachment 182688

Will the Devcon work for filling the bottom of the exhaust port and hold up to the heat ???? JB weld won't. And I use JB on intake port's without a problem.

 

[Deets066]

Will the Devcon work for filling the bottom of the exhaust port and hold up to the heat ???? JB weld won't. And I use JB on intake port's without a problem.

What’s the benefit to filling the bottom of the exhaust port?

 

[Deets066]

I tried it on an old table saw. A piece of casting where a bolt hole was broke under the bolt hole. I cleaned the area with brake cleaner and drilled a few 1/16 th. holes and mixed both parts well and applied. It cured for about 7 days before I put motor back on and it felt very solid. After a little usage the weld broke loose. Another instance was on a steel water trough. I preppped the area as well as I knew how and applied and it lasted about 6 months and started leaking ,so I drained tank and noticed a fraction of space between weld and the galvanized so I took my nail and applied a little upward pressure and the whole patch came up. Possible I may not be applying correctly but I thought I took proper steps?

You should never surface prep with brake cleaner. It leaves a film that JB doesn’t like to stick to.

 

[ucm931]

You should never surface prep with brake cleaner. It leaves a film that JB doesn’t like to stick to.

I'll have to respectfully disagree with this one. It's gotta be something else. Brake cleaner itself leaves no film/residue behind. It may leave behind crud it dissolved if not cleaned up before it dries. It is formulated that way for a reason, anything left behind would be a liability. Someone could/would make the argument that it caused brake failure and an accident. Carb cleaner on the other hand sometimes leaves residues behind to lubricate moving parts.

 

[Yotaismygame]

 

[Basher]

What’s the benefit to filling the bottom of the exhaust port?

Many believe a piston at top dead center that leaves a gap between the bottom of the piston skirt and bottom of the exhaust port, freeporting, will cause a problem. This has not been the case with several saws I have run that had a slight freeport.

 

[MG porting]

What’s the benefit to filling the bottom of the exhaust port?

For themmmm dang big bores that have free port issues.lol

 

[ucm931]

View attachment 182751

8

You missed a spot.........

 

[Deets066]

Many believe a piston at top dead center that leaves a gap between the bottom of the piston skirt and bottom of the exhaust port, freeporting, will cause a problem. This has not been the case with several saws I have run that had a slight freeport.

I figured he was talkin about free porting but I have never seen it make a saw run worse

 

[Deets066]

I'll have to respectfully disagree with this one. It's gotta be something else. Brake cleaner itself leaves no film/residue behind. It may leave behind crud it dissolved if not cleaned up before it dries. It is formulated that way for a reason, anything left behind would be a liability. Someone could/would make the argument that it caused brake failure and an accident. Carb cleaner on the other hand sometimes leaves residues behind to lubricate moving parts.

@tree monkey had a video explaining it. Might be speculation, but I choose not to use it at the last step of prep.