- Thread starter decca
- Start date
waldershelf
Member
- Messages
- 547
It's just glorified filler. It's fine for filling none load baring metal components. For anything else forget it, the stuff about it fixing threads and stuff is rubbish.
PhillipM
Member
- Messages
- 3,007
Well that's what I call bravery - if any of it breaks off it's going straight to the valves, piston etc...
It's pretty common in the porting world, no real issue with it proving the prep is right - plenty of plastic inlet manifolds around that nobody bats an eye at
It's pretty common in the porting world, no real issue with it proving the prep is right - plenty of plastic inlet manifolds around that nobody bats an eye at
yeah need to rough the ports up to give the JB weld something to stick to....good preparation is the key, you could say
Dieselman 63
Forklift Certified
- Messages
- 5,681
- Location
- Wellington, New Zealand
I thought it was more an epoxy than a filler, the stuff I use is two part mix
Bill Edwards
Member
- Messages
- 4,959
- Location
- Scarborough, North Yorkshire
It's pretty common in the porting world, no real issue with it proving the prep is right - plenty of plastic inlet manifolds around that nobody bats an eye at
Plastic I'd not think twice about, it's a single solid piece - not exactly anything to go wrong that could cause it to break up and travel through the engine.
It's just that the idea of something such as JB weld (which I've not had much success with when I tried it a few years ago) which is getting subjected to a lot of changing temperature leaves me thinking about a chance of it breaking up.
But hey, I'm not knowledgeable about porting at all, just thinking about what would happen if the stuff came loose.
Fast steel type products and metal epoxy I've used quite a lot of in the past.
They are great I have found for plugging holes and bridging as well as adding material, but bonding things back together is normally quite poor. As people have said, if the two parts are keyed it stands a better chance, the more horribly mashed up and keyed the better so the epoxy can seep into the groves and cuts and give the outer stuff something to bind to or pull on, but ultimately, trying to attach anything with moderate weight and or force back together in my experience will fail. The Epoxy (especially if it is something that will have force applied IE a bolt or tightening) normally results in the epoxy being torn apart or cracked / twisted.
It's best use is bridging / plugging holes for which it goes a great job, but as you would expect, much like plaster and lath it mushrooms out somewhat around the edges and provides a solid plug. Most successful application I have found is on leaks, I've used it on rads and fuel tanks, as well as even blocks and sumps before, but I think that is it's limitation.
They are great I have found for plugging holes and bridging as well as adding material, but bonding things back together is normally quite poor. As people have said, if the two parts are keyed it stands a better chance, the more horribly mashed up and keyed the better so the epoxy can seep into the groves and cuts and give the outer stuff something to bind to or pull on, but ultimately, trying to attach anything with moderate weight and or force back together in my experience will fail. The Epoxy (especially if it is something that will have force applied IE a bolt or tightening) normally results in the epoxy being torn apart or cracked / twisted.
It's best use is bridging / plugging holes for which it goes a great job, but as you would expect, much like plaster and lath it mushrooms out somewhat around the edges and provides a solid plug. Most successful application I have found is on leaks, I've used it on rads and fuel tanks, as well as even blocks and sumps before, but I think that is it's limitation.
DAPPH
as dyslexik as I'm daft
- Messages
- 7,226
- Location
- Near to Cross Hands Llanelli SouthWales GB
I've used it on a 12 ton ancient Ruston Buycrus excavator's sump that was in use on a large inert landfill site . The operator had rotated the body over a massive slab of broken concrete which tore a hole in the rear right hand corner of the sump .. After draining it of oil , hitting the sump with a steam generator around the hole & cracks I trigger pack sprayed the damage with acetone to get it as clean / free of oil as possible.
Whilst it was drying & cooling a bit I welded up a three face corner box , then slapped in five tubes of JB in th hole &large cracks plus one smeared all over the mating surfaces & self tapped the cover in place . It was still there not leaking four years later so i'd say it's good for sealing under a screwed on patch .
I've tried it for repairing things under tension & found that much above 18 ounces of pulling or torsional pressure it fails .
If you use it in a fibre glass bandage ( plaster board self adhesive scrim /mesh tape in my case ) it can seal domestic water pipes in an emergency but you'll need to warm the drained pipe to help it set well before you put the water back on .
Whilst it was drying & cooling a bit I welded up a three face corner box , then slapped in five tubes of JB in th hole &large cracks plus one smeared all over the mating surfaces & self tapped the cover in place . It was still there not leaking four years later so i'd say it's good for sealing under a screwed on patch .
I've tried it for repairing things under tension & found that much above 18 ounces of pulling or torsional pressure it fails .
If you use it in a fibre glass bandage ( plaster board self adhesive scrim /mesh tape in my case ) it can seal domestic water pipes in an emergency but you'll need to warm the drained pipe to help it set well before you put the water back on .
