fomocoforrester
Well-known member
- Joined
- Jun 13, 2008
- Messages
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What if it was? - why is that even worth a comment? - You're not a homophobe are you?
God forbid ....
Brazing 101 ,the wonder glue
- Thread starter NASTYZEN
- Start date
What if it was? - why is that even worth a comment? - You're not a homophobe are you?
God forbid ....
Frank The Plumber
Well-known member
I have found that the big problem with this process is that you can not see the base weld repair. So you buy a part or a car with a repair such as this that has been blended and then shot with some paint. Then you find out that the guy who did this repair was a son of a jack rabbit after the part fails. If it's done proper it's OK, but if not, it's just plain ****.
And you have no way of knowing it unless you yourself actually did the repair. It seems that braze alloy can be BS'd and made to look better than it really is.
And you have no way of knowing it unless you yourself actually did the repair. It seems that braze alloy can be BS'd and made to look better than it really is.
Mario428
Well-known member
Not quite brazing but I saw someone mention silicon bronze with a TIG welder.
I put crossbolt caps in my FE motor, the purchased caps from Pro-GRam are nice but to install means cutting the webbing between the cap area and skirt and I did not want to do that.
One side of the block has cats bosses that can be used to set the cap against but the other side does not. So I built up bosses using silocon bronze using my tig, pre and post heated the block with a couple of propane torches.
Bronze stayed well enough to be machined though I did go very gentle.
Caps I made to fit
Use a spacer on each side with a tight sliding fit and then the bolt goes thru to tie the block skirts together side to side
I put crossbolt caps in my FE motor, the purchased caps from Pro-GRam are nice but to install means cutting the webbing between the cap area and skirt and I did not want to do that.
One side of the block has cats bosses that can be used to set the cap against but the other side does not. So I built up bosses using silocon bronze using my tig, pre and post heated the block with a couple of propane torches.
Bronze stayed well enough to be machined though I did go very gentle.
Caps I made to fit
Use a spacer on each side with a tight sliding fit and then the bolt goes thru to tie the block skirts together side to side
That's what I meant,cracked edges or the entire corner gone.The part must be prepared accordingly. Ie. v grooving.I've brazed between chambers with success before.More often than not it's been a repair because the engine guy broke into a water jacket while porting.
For thread repair I will usually go with a helicoil or machine a threaded insert on my lathe.
It's like anything,if you don't know what your doing ,garbage in ,garbage out....
Brazing is a skill you develop just like any other process.
Brazing saves the day again.
Cast iron concrete pump thing with broken ears.
First step, take some of the **** off of it and wire brushing.
Then grinding all the surfaces clean that need to be rebuilt.In most cases I find that rebuilding from scratch is more durable than trying to braze the broken ear back on again.
With big heavy stuff like this I use my cutting torch for a heat source. I use coated brazing rod to wick the surface first. The flux on them is more aggressive than my fluxer and will stick better to the rough surfaces.
Once the wicking step is complete I switch to a bare rod. In this case 1/8 dia. low fuming bronze. You don't need flux to have bronze stick to bronze and it's cheaper than the coated ones.
Looks awful, no?
The end result, after dressing and machining.Ready for more abuse.
A guys, remember the darn torch stays real hot, even after it's been turned off...
Cast iron concrete pump thing with broken ears.
First step, take some of the **** off of it and wire brushing.
Then grinding all the surfaces clean that need to be rebuilt.In most cases I find that rebuilding from scratch is more durable than trying to braze the broken ear back on again.
With big heavy stuff like this I use my cutting torch for a heat source. I use coated brazing rod to wick the surface first. The flux on them is more aggressive than my fluxer and will stick better to the rough surfaces.
Once the wicking step is complete I switch to a bare rod. In this case 1/8 dia. low fuming bronze. You don't need flux to have bronze stick to bronze and it's cheaper than the coated ones.
Looks awful, no?
The end result, after dressing and machining.Ready for more abuse.
A guys, remember the darn torch stays real hot, even after it's been turned off...
mrpowderkeg
Well-known member
Brazing is probably the most handy thing to be able to do that no one else in your group knows how to do. I use it for quick fixes, odds and ends, like making a -06 male adapter to 5/16 inverted male flare for a transmission cooler line (adapted a -06 male an fitting to a piece of metal fuel hardline), brazing on transmission drain plug fittings so you can install a drain plug in a transmission, oil pans etc... One thing I cannot do yet, but I know a guy who has done it, is use a tig torch to heat the metal enough to braze, he does this on high end race cars to hold light duty mounts
fergus
Well-known member
Dang Claude....thanks for another lesson!
Murphy4570
Well-known member
Oh I need to go buy bronze rod now and go empty the tanks on my cutting torch by teaching myself how to braze stuff.
I have an old drum type fan. If that's the right word for it. I changed the pulley ratio, so now it ***** like heck. A good thing, because that cement pump was full of acrid smelling grease! I open my garage door about 6 inches for optimal ventilation.
For winter, well, it get's to -30C here. Fahrenheit equivalent for you Southern blooded souls( f'n cold!!) you may die!
I wear a winter jacket and freeze my ears off cause my tuque wont fit under my welding helmet..
My I suggest you use your smaller tipped Oxy-Ace welding torch for practicing on thin stuff first. Your tanks will last you much longer.
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ha ha.. "tuque"
i could raise my door, i guess, something like that fan... but i would have to have all my brazing wishes lined-up for one day's worth of work.
maybe fab a vent hood, but i know that would jinx me into never having a fab project that fits on a bench under a hood.. -- i'm not very close to getting to this point.. bah!
.
i could raise my door, i guess, something like that fan... but i would have to have all my brazing wishes lined-up for one day's worth of work.
maybe fab a vent hood, but i know that would jinx me into never having a fab project that fits on a bench under a hood.. -- i'm not very close to getting to this point.. bah!
.
darkk
Well-known member
I brazed for many years, but that was also many years ago......
Griff93
Well-known member
What are you using to work the built up bronze back down? This is the part that always seems to really **** when I repair stuff using brazing rod.
I used to have a mobile hood, took it out cause all the smoke would accumulate against the ceiling anyway. This setup really does a better job.
Most of the time I use a hand held grinder. Starting with coarse disks and finishing with 120 grit ******* type disks.
When I can or when it matters I use my milling machine.
Nealcrenshaw
Well-known member
That was good demonstration of brazing,i've also been watching a guy on youtube that uses the same technique if you get a chance check out some of his videos.
His Channel is KEF791.
A good video of this technique of his is"So you broke it off in your hole Pt1 & Pt2."
His Channel is KEF791.
A good video of this technique of his is"So you broke it off in your hole Pt1 & Pt2."
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kald
Well-known member
I have an old drum type fan. If that's the right word for it. I changed the pulley ratio, so now it ***** like heck. A good thing, because that cement pump was full of acrid smelling grease! I open my garage door about 6 inches for optimal ventilation.
For winter, well, it get's to -30C here. Fahrenheit equivalent for you Southern blooded souls( f'n cold!!) you may die!
I wear a winter jacket and freeze my ears off cause my tuque wont fit under my welding helmet..
My I suggest you use your smaller tipped Oxy-Ace welding torch for practicing on thin stuff first. Your tanks will last you much longer.
Nice thread! I don't own a tig so any thin stuff gets brazed. It is actually faster for me any way since I do a ton of OA lead welding and I'm usually already set up for it.
P.S. WTF!! I had to google -30 celcius to see how cold that is, -22f! Damn as a native Floridian I've only been in really cold weather up north a few times (0f) and my snot froze, can't imagine -22. How do you guys live up there?
graybeard62
Member
Nice jobBrazing saves the day again.
Cast iron concrete pump thing with broken ears.
First step, take some of the **** off of it and wire brushing.
Then grinding all the surfaces clean that need to be rebuilt.In most cases I find that rebuilding from scratch is more durable than trying to braze the broken ear back on again.
With big heavy stuff like this I use my cutting torch for a heat source. I use coated brazing rod to wick the surface first. The flux on them is more aggressive than my fluxer and will stick better to the rough surfaces.
Once the wicking step is complete I switch to a bare rod. In this case 1/8 dia. low fuming bronze. You don't need flux to have bronze stick to bronze and it's cheaper than the coated ones.
Looks awful, no?
The end result, after dressing and machining.Ready for more abuse.
A guys, remember the darn torch stays real hot, even after it's been turned off...
69lm69gp
Well-known member
I have some thing I need to braze. But I am concerned about the casting cracking as it cools. I know you can bury it in sand of lime to slow the cooling to prevent the cracking. But I would like to practice first on a piece of scrap first. Do you think and old disc brake rotor would work for this purpose?
Mike
Mike
trainer
Well-known member
I did a brazing repair on the tool holder for my wood lathe a few weeks ago. I was in a hurry to to get it back up and running so i didnt grind everything smooth when i was finished. I vee'd out the breaks as much as could and I roughed the surfaces up a 24 grit disc to give the bronze some teeth to stick to.
In general, you want as much surface area as practical, clean as possible, and rough it up if possible.
Also correct the reason that the original part broke.
I had a friend who swore that brazing was **** because his repairs kept breaking on a snowmobile muffler. The problem was that that something was mis-aligned and he had to beat it to get it to go back on after it was repaired. This put stress on the part that caused it to fail in the first place Once we took the time to align everything, it outlasted the sled.
In general, you want as much surface area as practical, clean as possible, and rough it up if possible.
Also correct the reason that the original part broke.
I had a friend who swore that brazing was **** because his repairs kept breaking on a snowmobile muffler. The problem was that that something was mis-aligned and he had to beat it to get it to go back on after it was repaired. This put stress on the part that caused it to fail in the first place Once we took the time to align everything, it outlasted the sled.
Attachments
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I've never had cracks from the metal cooling on castings..yet. If you use sand, make sure it's 100% dried. dry it for a 1/2hr in a stove. (while she's at work
)Preheating your part first will go a long way in preventing cracking or even letting it cool in an oven , gradually reducing the heat over several hours.
Practicing on scrap first is a good way to go for sure.
Quick and sturdy.
Not grinding off the excess weld buildup makes it even stronger. But you may want to wire brush the flux off to prevent corrosion over time.is it true that braze joints conduct heat more efficiently than welded joints? in an application like the interface between exhaust runners and the header flange, it becomes advantageous as the retention of heat increases exhaust velocity. wondering if anyone has had any experience with this, as i'll be building headers from scratch for my swap project in the near future.
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v7guy
Well-known member
I have always read that you couldn't braze/fuse stainless. For example you could never think of making a set of stainless headers with an O/A setup.
Is this incorrect info?
Is this incorrect info?
So, pretend you broke an ear off the starter mounting boss on a cast iron SBC (this is a common problem), would this be a good way to make the repair? I'm assuming this could not be done with the engine still in the vehicle. What would the process be to repair the block?
Not sure bronze would conduct heat more than the actual base metal.
Bronze is more ductile than steel and will deform a long way before breaking though.
I would not use bronze on headers. There is no penetration when brazing, only cap welding or gluing. I have only used it on road cars as tacks between tubes to keep them from turning or moving. Mister muffler only had Oxy-Ace setups back in the day before migs were common.
I have made lots of money repairing track side repairs made to headers on race cars. You have to cut out the brazed repair and replace with new then T.i.G for it to have any chance of lasting.
You can braze S/S no problem but you can't fuse it with Oxy-Ace.
T.I.G. is the way to go with any type of materials for headers.
Whats an SBC ?
The method I use to repair a broken off cast iron ear is the same as the one depicted in the cement pump repair.
On the bench is always easier but it could be done in the car if there is nothing to burn near where the brazing needs to be done. Keep a fire extinguisher near by....You can overhead braze, just don't stand directly underneath, because it tends to drip a bit, and its hot!
You will learn the welders dance in a hurry!!
The next time you make a rough interupted cut with that, it'll likely break again, so be prepared for that. That is probably the weakest point on inexpensive wood lathes.
Did that too, on one I had so I fabricated a new one with 1 X 3/8" bar. No pictures, as that lathe was sold a few years ago.
SBC = Small Block Chevy
kald
Well-known member
I have had good success brazing large stainless fixed resisters to heavy gauge copper solid core wire for electrical applications.
D.J.
Well-known member
Very good info here. I started out using wire coat hangers to "braze" exhaust pipes in Dads service station back in the 70's with oxy-ace even though we had a Forney very expensive in its day Stick welder ( couldn't get setting hot enough for good penetration without blowing holes in pipes). I don't want to hijack but was at the Frog Follies over the last weekend and saw a booth for the DHC 2000 by Cobra torches (www.cobratorches.com) and was wondering if anyone uses this type setup for oxy ace?
If you were using coat hangers you were fusing. Brazing requires a bronze or silver alloy rod.
Unless you were using bronze coat hangers.
In school we had bare rod and had to heat up the rod and then dip in a can of powder flux.
That torch is like the Dillon torch. it's ok. But I like my Harris better. I dont find it comfortable.
AWS (American Welding Society) definitions:
soldering - using a filler metal that melts at a temperature below 450C/842F.
brazing - using a filler metal that melts at a temperature above 450C/842F, but does not invlove melting of the 'parent' metal(s), and where the molten filler is drawn into the joint via capillary action.
welding - where you melt the parent metal as well as the filler.
There are some gray areas or areas of (potential) confusion where you may have the same filler but in one case the parent metal melts (welding) but in the next the parent metal doesn't melt (brazing). Happens with some of the aluminum alloys (parent and filler metals), not so much with steel though.
D.J.,
If you were melting a steel coat hanger with an oxy-acetylene flame and melting the parent steel metal as well, then you were (crudely) welding. Crudely welding because you were using a filler of pretty much unknown alloy and properties.
jhelrey,
You have a 'broken' cast iron item. Brazing may or may not be an appropriate fix. You kind of have to give a bit more info about the broken item and the sort of usage and environment it has to hold up to. A cast iron trivet that broke? Sure, brazing will probably work (given the appropriate user skill and filler/flux being used). A broken cast iron turbo housing? Maybe or maybe not, depending on which brazing filler you choose. Probably I'd tend more towards a nickel filler weld there as a lower melting temp 'brazing' filler may not hold up to the usage temperature. Etc, etc.
soldering - using a filler metal that melts at a temperature below 450C/842F.
brazing - using a filler metal that melts at a temperature above 450C/842F, but does not invlove melting of the 'parent' metal(s), and where the molten filler is drawn into the joint via capillary action.
welding - where you melt the parent metal as well as the filler.
There are some gray areas or areas of (potential) confusion where you may have the same filler but in one case the parent metal melts (welding) but in the next the parent metal doesn't melt (brazing). Happens with some of the aluminum alloys (parent and filler metals), not so much with steel though.
D.J.,
If you were melting a steel coat hanger with an oxy-acetylene flame and melting the parent steel metal as well, then you were (crudely) welding. Crudely welding because you were using a filler of pretty much unknown alloy and properties.
jhelrey,
You have a 'broken' cast iron item. Brazing may or may not be an appropriate fix. You kind of have to give a bit more info about the broken item and the sort of usage and environment it has to hold up to. A cast iron trivet that broke? Sure, brazing will probably work (given the appropriate user skill and filler/flux being used). A broken cast iron turbo housing? Maybe or maybe not, depending on which brazing filler you choose. Probably I'd tend more towards a nickel filler weld there as a lower melting temp 'brazing' filler may not hold up to the usage temperature. Etc, etc.
Monkey_Wrench
Well-known member
I've been using MAP gas (Yellow bottle/burner) to try and braze. I've had mediocre luck, only smaller items I was able to braze.
Should I invest in an Oxy-acetylene setup instead?
Should I invest in an Oxy-acetylene setup instead?
metaleltr
Well-known member
Yes, as you have discovered a mapp gas torch only works for small scale brazing.
You need more heat.
Yes Oxy-Ace is the way to go, in my opinion. I've seen complete sets go for $50 bucks at flea markets.
The only thing I've had go bad in a gauge is the diaphragm.You can get those replaced cheaply. Torches have small O rings in the removable head simple, replacement with every day O ring fixes that.
If you can afford it, buy new, just make sure it doesn't say made in China on it.
I'm sure they make a good one, but I've come across more bad than good from there so far......
Harris and Victor are good ones to start with. They used to make them here....
trainer
Well-known member
The way it works is that the hex head fits in the shoulder on the tool rest. A lever is attached to the bolt underneath and it gets moved often while turning a piece, so using a wrench wouldn't work. I guess the solution would be to make something that had more surface area but still caught the shoulder.
When i get time i may re- engineer this part using mild steel so it takes more punishment
chris fresh
Well-known member
DAMN! that's pretty,very nice work on that.that's what i love about this board,seein what "real craftsman" can do,i know way to many guy's that would have bought new,i do the same as you and fix what i'm capable of.guy's around me are amazed at what can be done,i always say,what if there wasn't another one to buy? what would you do?Brazing saves the day again.
Cast iron concrete pump thing with broken ears.
First step, take some of the **** off of it and wire brushing.
Then grinding all the surfaces clean that need to be rebuilt.In most cases I find that rebuilding from scratch is more durable than trying to braze the broken ear back on again.
With big heavy stuff like this I use my cutting torch for a heat source. I use coated brazing rod to wick the surface first. The flux on them is more aggressive than my fluxer and will stick better to the rough surfaces.
Once the wicking step is complete I switch to a bare rod. In this case 1/8 dia. low fuming bronze. You don't need flux to have bronze stick to bronze and it's cheaper than the coated ones.
Looks awful, no?
The end result, after dressing and machining.Ready for more abuse.
A guys, remember the darn torch stays real hot, even after it's been turned off...
damn nice work man!