I did a successful repair on a cast iron exhaust manifold. With it off I ground in a V channel around the break about half deep, held the parts in a jig and arc welded in a spot type pattern, one side 1/4 inch long weld using high nickel fluxed rod, than opposite side, than perpendicular, than opposite. all the time keeping a propane torch on the adjacent sides of the weld to keep it pretty hot. I filled in the rest using the same opposite and adjacent weld pattern. I thing it was AC arc and 1/8 inch rod. After finishing all the welds I wrapped the manifold in fiberglass insulation and let it cool. Than I ground down the weld to near surface level and checked for holes and slag. It came out pretty good for my first attempt. It lasted the 5 years I ran the car and sold it still intact. It was a very unusual manifold and I could not find a used one.
I was glad to see you’ve installed external flashback arrestors on your torch! Not to be confused with reverse flow check valves, flashback arrestors are a very wise thing to have on any torch, but few are the times that you see them! Good.job, and stay safe! 1978 graduate.
I have a 20 or so gallon barrel full of lime I use sometimes for annealing and cast braze projects. Usually solves lots of issues, little messy at times, but not big deal, washes off with water!! Good job!!!!
@SuperMetalG A general purpose Brazing Alloy, low fumming , HT: 1004-1104 and the high heat flux #2 for the fist pass, second pass, you can switch to #1 flux if you choose too!
Thanks Keith I always learn from the jobs you do. I did miss the 70's music, you always have the radio on? Hey I grew up in the 70's, well they were my high school years anyways not so sure about growing up!. Keep them coming.
I use a general purpose low fuming brazing rod AWS (RBCuZn-C) A5.8-92/ASME SFA5.8-92 if that helps at all, and I like Peterson #2 high heat flux power. Do full prep as you would do for a weld and if it is a crack and not a broken off piece, drill a hole at the end of the crack so you keep it from traveling further. ;{)-----
@ROCKNTV1 I have repaired lots of cast gears missing gear teeth, by brazing, filling the void and remachining. Ideal, is cutting teeth with proper pitch and cutter # holding it with an index head. But I have form tooled a cutterbit, ran it like a fly cutter, held the gear on a mandrel, using the other teeth to index the cuts. best results is when you remove the whole tooth or set of teeth needing repair, good luck John... Keith
I know folks are reluctant to electro weld cast but with modern nickle rod and drillings the crack ends pre heating then site heating welding and quickly grinding surface flat ,annealing then slow cool and reheat, you will have a dimentionaly stable repair that will not re crack and will exceed the ability of bronze to withstand heat you can even follow up with bronz for porus hole fill
@Jim911Bo Thanks, I graduated in 75, right on the beach of Oceanside! I'm with you, if growing up means you have to stop playing, not going to happen!... LOL... Keith
There are a couple other videos in my collection that give a better glimpse of the droplet transferring. They are Brazing knuckles and the Deer John videos; I do a lot of brazing and will continue to try getting that magic window! ;{)---
When you push the heat, you’re also pushing the flux, like the hard pack before the asphalt. The metal is brought up to temp and the flux spreads out and then you drop molten droplets onto the base material as the torch passes by sort of below and behind the force of the flame! It joins much smoother and has less gas pockets, than would be formed if dragging the puddle, which actually blows back into the puddle itself, forcing everything within. ;{)---
I've never tried brazing before, and I want to braze the small cracked to my exhaust manifold, what kind of brazing or soldering rod [material] do you recommend for cast iron?. I'm planning to rent an oxy/acetylene torch.
Keith, love the videos. What brand/type blankets are you using as wraps to slow the cooling? Are there alternatives for cooling a cast braze job? I've heard of burying in dry sand. Thanks and keep up the great work and education!
I had some bitter experiences with these nickel rods when fitted a turbo flange to a cast iron manifold (though was a newbie to welding) What type of brazing rod and flux you find best suited for the job? Because there are various types at least HILCO has 4 types of brazing rods.. thanks in advance!
First of all keep up the good vids,. well done! I understand through your comments that you prefer brazing cast iron so that the joint is not hardened and on cooling shrinkage stresses would be less. But I have at hand to do a repair of a gearbox housing of a 2.5ton 4wd concrete dumper. The joint should resist quite a number of shock loads, I am considering heating the housing in a large BBQ and weld with nickel rods and then post heat, what do you recommend from experiences?
hey keith i made a small 1/8 inch hole in a water jacket on my head while porting the heads. would brazing be a more effective approach to repairing this? how reliable would it be on the exhaust port where temps can get pretty high? i feel more confident in repairing this common rookie blunder after watching this video.
@KEF791 yeh man, a bunch are missing from my 11x24 i thought the same way about the involute fly cutter and indexing from the gear itself , the gear has been repaired before but are very expensive new , so i am looking at making the complete thing myself either a casting or from my weight bench, lol
Would it be ok after finishing brazing you apply heat evenly then have a charcoal grill ready then after finishing with the heat distribution you place the part on the grill (covered) and allow the charcoal to slowly die out or is that over kill?
I have pre heated on the top of the wood stove before and getting the cast material up to around 400 to 500 F helps get the part ready for the final local heating at the weld area! ;{)-----
Why would you go through all that when you have a torch right there in your hand that you have to use to heat up the material enough to actually braze it..🧐
Heat it until just under cherry red, stick weld using nickel rods, place in a bin of sand or vermiculite and leave for 24hrs to cool sloooowly :) nice job with the bronze :)
To repair a small crack on an engine, can I simply do it in its location. Or do I have to remove the oil and work in an open area? I was planning to do the same thing you are doing but while is still mounted on the boat. Thank you for you feedback in advance.
That is a hard one to answer without knowing where or what position it is in, how safe is the zone around where you are working for hot work etc. ;{)------
Javier Ruiz I would be looking for another block if that is what you are referring to, your going to play heck with a crack traveling into the interior cavities of the casting. ;{)------
Cast iron manifolds like this, what other ways can you weld them up other than this brazing your doing, can you weld it with a tig/stick/mig welder? btw really cool channel you got here you got some mad skills :)
Martin møller Not that familiar with welding, but I think that welding cast iron tends to make it very brittle because of the graphite phase and how hot the arc gets.
Well, on the maganezee Bronze, I don't care to deal with the fuming and spitting and on the cast iron manifold, I don't like to take a chance on crystlizing the material near the bond...
Keith Fenner Thank you for answering me! If only this was around when I was a kid! I called four welding supply companies here and no one knew for sure. Jeeez! I plan on doing a pre-heat and a post heat for this block. Now to find a free oven on Craigs List. hahaha
With the Cobra torch, it'll make fabricators, boilermakers and other maintenance men look like professional welders. In brazing, I don't see much difference if it was done by oxy-fuel, MIG or TIG.
+Seph Angelo cobramatics you have to unlearn how to weld , and relearn I had been welding for years and had to break alot of habits and ideas like pushing welds was a no no and welding down hill was a no no it made my welds stronger better looking , quicker flute pass and less internal stressed more root stress and cooler cap welds , every man should have one even an old one
Bryan Dunlop Thanks for your comment, it helped as I brazed a crack on a Stanley No.71 router plane today. I used low fuming bronze rod, I then covered the work for 1 1/2 hours under 3 pairs of welding gloves to cool slowly.
My experience nickel rod repair are about one half as successful as brazing repairs, more so on holding from leaks and handling impacts. Remember though if the driving techniques remain the same chances are it will break again. ;{)-----
The bonding of the brazing process is a better choice than creating a molten puddle in ductile materials, which becomes brittle after cooling. ;{)-----
Keith Fenner It'd be cool to see you use a TIG on really low heat to braze. Could you try that out? As in, the amps so low it doesn't melt but gets up to brazing heat?
Keith Fenner in college (for automotive mechanic) we had to learn brazing, I ended up working more in heavy equipment and such and years later i actually have brazed a ton of things and usually have good results. The only thing is though is the instructor every day told me to never braze exhaust, especially a manifold because it would get too hot and it wouldn't last. can someone set me straight on the facts here?
I would not braze a turboed exhaust manifold that could easily gets dull red. However, i would not hesitate to repair naturally aspirated manifold or exhausting piping downstream. I have done that many many times without failure. I think the key point to consider is the operating temperature.
I guess everybody has their own techniques, I would not have brazed it that way, To much oxygen to big of a flame tip, Look at that pile of braze sitting there, now your going to grind it all down to make it pretty, Rubbish. Pre heat with that tip is fine, the metal is already hot drop down one tip size and you could actually gas braze that manifold like you were using a Tig Torch.
Never braze an exhaust manifold. Cheaper at that point to go to the junkyard and find one that's in better condition. Maybe brazing a muffler would work. But not the manifold lol.
75' I graduated in 76 whatda know, western suburbs of chicago.
Thanks again for taking the time to set up your cam and sharing your skills.
Keith Fenner: One of the few who could tackle the Liberty Bell crack - and succeed! Thanks for another great video!
I did a successful repair on a cast iron exhaust manifold. With it off I ground in a V channel around the break about half deep, held the parts in a jig and arc welded in a spot type pattern, one side 1/4 inch long weld using high nickel fluxed rod, than opposite side, than perpendicular, than opposite. all the time keeping a propane torch on the adjacent sides of the weld to keep it pretty hot. I filled in the rest using the same opposite and adjacent weld pattern. I thing it was AC arc and 1/8 inch rod. After finishing all the welds I wrapped the manifold in fiberglass insulation and let it cool. Than I ground down the weld to near surface level and checked for holes and slag. It came out pretty good for my first attempt. It lasted the 5 years I ran the car and sold it still intact. It was a very unusual manifold and I could not find a used one.
I was glad to see you’ve installed external flashback arrestors on your torch! Not to be confused with reverse flow check valves, flashback arrestors are a very wise thing to have on any torch, but few are the times that you see them! Good.job, and stay safe! 1978 graduate.
Hi Dan, thanks for the comments, I have a few other videos with brazing as the main medium, like brazing Knuckles and Deer John. ;{)---
I have a 20 or so gallon barrel full of lime I use sometimes for annealing and cast braze projects. Usually solves lots of issues, little messy at times, but not big deal, washes off with water!! Good job!!!!
Wow, what great work on the manifold, I guess that is easy compared to the bronze alloy part and it looked GREAT!
@SuperMetalG A general purpose Brazing Alloy, low fumming , HT: 1004-1104 and the high heat flux #2 for the fist pass, second pass, you can switch to #1 flux if you choose too!
I always like to come back to this one even know every on of Keiths videos are great but what do I know right lol.
Thanks Keith
I always learn from the jobs you do.
I did miss the 70's music, you always have the radio on? Hey I grew up in the 70's, well they were my high school years anyways not so sure about growing up!.
Keep them coming.
cool to see that people still use oxy-acetylene over tig. pretty cool.
hey bro , thanks for the tip on drilling a hole at each end of a crack to stop it from advancing, love your videos,
keep up the cool vids.i love learning new things from cool people.
For most cases I prefer my #3 tip, I can start by cranking it up to soak the heat, then tone it down for applying braze...
great job brazing.. and i LOVE the old gang drill press table.... u don't see them often !!
nice work!
I use a general purpose low fuming brazing rod AWS (RBCuZn-C) A5.8-92/ASME SFA5.8-92 if that helps at all, and I like Peterson #2 high heat flux power. Do full prep as you would do for a weld and if it is a crack and not a broken off piece, drill a hole at the end of the crack so you keep it from traveling further. ;{)-----
very good video Keith.
@ROCKNTV1 I have repaired lots of cast gears missing gear teeth, by brazing, filling the void and remachining. Ideal, is cutting teeth with proper pitch and cutter # holding it with an index head. But I have form tooled a cutterbit, ran it like a fly cutter, held the gear on a mandrel, using the other teeth to index the cuts. best results is when you remove the whole tooth or set of teeth needing repair, good luck John... Keith
I know folks are reluctant to electro weld cast
but with modern nickle rod and drillings the crack ends
pre heating then site heating welding and quickly
grinding surface flat ,annealing then
slow cool and reheat, you will have a dimentionaly
stable repair that will not re crack and will exceed
the ability of bronze to withstand heat
you can even follow up with bronz for porus hole
fill
extremely awesome work
@Jim911Bo Thanks, I graduated in 75, right on the beach of Oceanside! I'm with you, if growing up means you have to stop playing, not going to happen!... LOL... Keith
There are a couple other videos in my collection that give a better glimpse of the droplet transferring. They are Brazing knuckles and the Deer John videos; I do a lot of brazing and will continue to try getting that magic window! ;{)---
As long as the project of repair never get as hot as the process of brazing itself, there is no problems! ;{)-----
When you push the heat, you’re also pushing the flux, like the hard pack before the asphalt. The metal is brought up to temp and the flux spreads out and then you drop molten droplets onto the base material as the torch passes by sort of below and behind the force of the flame! It joins much smoother and has less gas pockets, than would be formed if dragging the puddle, which actually blows back into the puddle itself, forcing everything within. ;{)---
loved your cool down protocal
was this of the same strongness with the welding machine since it as well make a bond by melting?
I've never tried brazing before, and I want to braze the small cracked to my exhaust manifold, what kind of brazing or soldering rod [material] do you recommend for cast iron?. I'm planning to rent an oxy/acetylene torch.
Keith, love the videos. What brand/type blankets are you using as wraps to slow the cooling? Are there alternatives for cooling a cast braze job? I've heard of burying in dry sand. Thanks and keep up the great work and education!
I had some bitter experiences with these nickel rods when fitted a turbo flange to a cast iron manifold (though was a newbie to welding) What type of brazing rod and flux you find best suited for the job? Because there are various types at least HILCO has 4 types of brazing rods.. thanks in advance!
A piece of mind! Knowing that I didn't create any hard spots that may develop a stress rise area in the part. ;{)-----
First of all keep up the good vids,. well done! I understand through your comments that you prefer brazing cast iron so that the joint is not hardened and on cooling shrinkage stresses would be less. But I have at hand to do a repair of a gearbox housing of a 2.5ton 4wd concrete dumper. The joint should resist quite a number of shock loads, I am considering heating the housing in a large BBQ and weld with nickel rods and then post heat, what do you recommend from experiences?
hey keith i made a small 1/8 inch hole in a water jacket on my head while porting the heads. would brazing be a more effective approach to repairing this? how reliable would it be on the exhaust port where temps can get pretty high? i feel more confident in repairing this common rookie blunder after watching this video.
@KEF791 yeh man, a bunch are missing from my 11x24 i thought the same way about the involute fly cutter and indexing from the gear itself , the gear has been repaired before but are very expensive new , so i am looking at making the complete thing myself either a casting or from my weight bench, lol
Would it be ok after finishing brazing you apply heat evenly then have a charcoal grill ready then after finishing with the heat distribution you place the part on the grill (covered) and allow the charcoal to slowly die out or is that over kill?
I was waiting for you to remove the studs......lol!
The braze did make full penetration even puddling though to the inside, hence the burr prep I did down to just a before breaking through. ;{)-----
Hey Keith, What do you think about pre-heating a part like this in an oven? If so, what temp?
I have pre heated on the top of the wood stove before and getting the cast material up to around 400 to 500 F helps get the part ready for the final local heating at the weld area! ;{)-----
Why would you go through all that when you have a torch right there in your hand that you have to use to heat up the material enough to actually braze it..🧐
Oh I wish I could find the one where there is a spider in his welding helmet, love it
Heat it until just under cherry red, stick weld using nickel rods, place in a bin of sand or vermiculite and leave for 24hrs to cool sloooowly :) nice job with the bronze :)
Is it ok to braze a handle back onto a pot?.. Does it contaminate the food?
good to know, thanks for the reply
To repair a small crack on an engine, can I simply do it in its location. Or do I have to remove the oil and work in an open area? I was planning to do the same thing you are doing but while is still mounted on the boat. Thank you for you feedback in advance.
That is a hard one to answer without knowing where or what position it is in, how safe is the zone around where you are working for hot work etc. ;{)------
Keith Fenner its just below the header. Its a 1980 mercruiser 228 (305ci). The crack leaks water. Is it still safe?
Javier Ruiz I would be looking for another block if that is what you are referring to, your going to play heck with a crack traveling into the interior cavities of the casting. ;{)------
i only brazed aluminum, and it says the heated metal should melt the rod never but in flame, not the same for all brazing?
is it better to push the weld ?? i always pull the weld with the heat
well done!
cool vid bud, considering methods to fix a cast iron back gear on one of my machines,, argh
Cast iron manifolds like this, what other ways can you weld them up other than this brazing your doing, can you weld it with a tig/stick/mig welder? btw really cool channel you got here you got some mad skills :)
Martin møller Not that familiar with welding, but I think that welding cast iron tends to make it very brittle because of the graphite phase and how hot the arc gets.
Well, on the maganezee Bronze, I don't care to deal with the fuming and spitting and on the cast iron manifold, I don't like to take a chance on crystlizing the material near the bond...
What brazing rod is best used on an engine block from 1968?
Brazing rod is still the same and low fuming is the best and # 2 high heat flux. ;{)-----
Keith Fenner Thank you for answering me! If only this was around when I was a kid! I called four welding supply companies here and no one knew for sure. Jeeez! I plan on doing a pre-heat and a post heat for this block. Now to find a free oven on Craigs List. hahaha
i broke a easy out in on a honda atc cam chian tensioner on the piston jug what can i do or who can i take it to who nows what there doing
With the Cobra torch, it'll make fabricators, boilermakers and other maintenance men look like professional welders. In brazing, I don't see much difference if it was done by oxy-fuel, MIG or TIG.
+Seph Angelo cobramatics you have to unlearn how to weld , and relearn
I had been welding for years and had to break alot of habits and ideas
like pushing welds was a no no and welding down hill was a no no
it made my welds stronger better looking , quicker flute pass and less internal stressed
more root stress and cooler cap welds , every man should have one even an old one
I think bluing will go into cracks to make them more visible. Of course that will have to be cleaned off as well.
thanks.. Hilco have that exact grade .. t
What braze did you use?
Yes! Yes !Yes! Acetilén dúsan ! Carbon pótlás ! És homok ágy 24 h.
What rod did you use
I would use a lot less oxygen for better control of weld puddle.
Bryan Dunlop Thanks for your comment, it helped as I brazed a crack on a Stanley No.71 router plane today. I used low fuming bronze rod, I then covered the work for 1 1/2 hours under 3 pairs of welding gloves to cool slowly.
good as new
thanks
do you ever peen your cast iron when done?
My experience nickel rod repair are about one half as successful as brazing repairs, more so on holding from leaks and handling impacts. Remember though if the driving techniques remain the same chances are it will break again. ;{)-----
So brazing is better than nickel rods?Also what type of flame did you use on the manifold?Was it oxidizing flame?Thank you.
I was under the impression brazing was not a suitable process for parts subjected to heat?
look on the websites weldfabulous or cyberweld under welding blankets they have them on there
Or better yet, throw away the cracked manifold and get a set of headers... just kidding. Good welding!
great but why not electric welding ?
seems to me that brazing is some sort of gluing processes
The bonding of the brazing process is a better choice than creating a molten puddle in ductile materials, which becomes brittle after cooling. ;{)-----
Keith Fenner It'd be cool to see you use a TIG on really low heat to braze. Could you try that out? As in, the amps so low it doesn't melt but gets up to brazing heat?
Keith Fenner
in college (for automotive mechanic) we had to learn brazing, I ended up working more in heavy equipment and such and years later i actually have brazed a ton of things and usually have good results. The only thing is though is the instructor every day told me to never braze exhaust, especially a manifold because it would get too hot and it wouldn't last.
can someone set me straight on the facts here?
I would not braze a turboed exhaust manifold that could easily gets dull red. However, i would not hesitate to repair naturally aspirated manifold or exhausting piping downstream. I have done that many many times without failure. I think the key point to consider is the operating temperature.
Absolutley correct.
Well very beautiful
cool
great repair--
keith, please check out the products at muggyweld and let us know what you think. thanks!
If you can get to it with easy and have success with your bond, you could save it! ;{)---
Маладец. Но медленно всё .
Keith sorry to be pedantic but I think you still had a hairline crack at the bottom @7:45
牛逼
A general purpose Low fuming brazing rod. ;{)----
You can’t even hear a word your saying..
I guess everybody has their own techniques, I would not have brazed it that way, To much oxygen to big of a flame tip, Look at that pile of braze sitting there, now your going to grind it all down to make it pretty, Rubbish. Pre heat with that tip is fine, the metal is already hot drop down one tip size and you could actually gas braze that manifold like you were using a Tig Torch.
Yep, you,re 100% right
Please don't do the music over the fast forward. It jarrs and breaks the flow of watching you work.
Hope you have rear exhaust on you die grinder. Those carbide burrs sure make some mean slivers. Enjoy your videos and setups.
Never braze an exhaust manifold. Cheaper at that point to go to the junkyard and find one that's in better condition. Maybe brazing a muffler would work. But not the manifold lol.