Machinist's Minutes: Brazing on cast iron

Knowing how to braze cast iron can save you from making sleeves or entirely new parts. It just takes practice!

[@greggallagher9978]

I rarely comment on videos but I just wanted you to know that I really appreciate your knowledge and realistic approach thanks bud

[@timelessengineering]

I also appreciate that he's not always hinting towards wanting tooling and money.

[@ypaulbrown]

watching those flames on a cold rainy night here is like having a fire place to watch. thanks John...... Paul

[@cpcoark]

I set my valves wherever I feel like. As you say, personal preference. Thanks for a refresher course on brazing.

[@lewiemcneely9143]

Sea bee Uncle was an ironworker and a killer on a torch and I've watched him do this a lot but it makes really good sense the way you do and tell about it and The photography was Par-Excellent!

[@johncollins719]

Very informative, thanks. I went to the local welding supply shop for some brazing rod about a year ago. The young guy at the counter didn't understand what I was asking for. He had to go in back and ask the boss. Brazing is somewhat of a lost art.

[@bobedd1040]

i just made good money doing some brazing

[@DonStinger]

Thanks for the detailed explanation. This cleared some things up for me despite having done some amount of cast iron brazing myself. Also very good camera work showing the adjustment of the flame. This is something that doesn‘t come through in most videos but is really obvious if you look at the flame with the naked eye or through shaded safety glasses. Greetings from Germany!

[@jeffmays3608]

From a fellow machinist that hasn't been at it quite as long as you... I just want to say I enjoy learning from and want to say thanks.

[@benjaminjordan2762]

I repaired a case trenches that the grease worms ate up by brazing it then cutting it down to fit. Saved the customer $400.00 by repairing the part instead of buying the only new part left in existence Case had. I did cover it in floor dry to cool slowly. I use borax for my flux in the forge and oxy/acetylene brazing and welding. Good informative videos, keep it up.

[@Hazmatt4700]

Having been of the "Figure it out yourself because you have no one to help you" school of welding, I can say that this is the best braising video I've ever watched. It confirmed all the correct and incorrect things I know I do. And the trick with putting the rods together was a great idea.

[@valkman761]

Man, this is exactly what I need I have a machine with split cast iron cover. Thank you!!

[@garybudge9786]

thanks for that video ,never watched or seen brazing being done on cast iron before so it is very interesting to hear how you set up the torch and go about the process

[@Nomadboatbuilding]

That was very informative. Thank you. Just in time for a vice repair I needed to do.

[@christianhilditch9333]

It so awesome of you to share these skills and tips. I have been a welder/Machinery repairman for 20years. You always have something to teach even if I just let the video play in the background for views. Thank you again Howie. It's about time you bent up a torch hanger. I know the torch should never leave your hand while lit, however when your alone, you do what you gotta do.

[@DaveyBlue32]

You’re just a fantastic amount of knowledge and I absolutely love the information that you dispense surrounding the properties and that why we want to do what we are doing… would love to have a dude like you to absorb knowledge from.,. Can’t believe that an old truck hub would be too cost prohibitive to build up but then again if you don’t have a replacement part available then you’ll have to do what you need to do to make it work again! LMFFAO! I’ve got a cast pulley from a air compressor that is broken out on the shoulder of the hub around the key way area that I’m going to try to braise back up.,, propane torch heat.,, big weed dragon or roll roof over type big heat torch maybe? I’m out of gas in my tanks??? Hopefully the propane will do it.,,

[@antihangfire]

An old trick that helps a lot with brazing is to draw a line with soap stone to contain the Flux in the area that you want to keep the brass in. Say if you're doing a 1/8" inch tee joint and want a 1/4" braze. Make a soap stone line on both base metal pieces at 1/4" where you want the Flux to stay.

[@GS-zv3qn]

Next lesson silver brazing , lot of people call siver soldering

[@ypaulbrown]

Great tip about using floor dry, to slowly cool brazed parts, it is also know as Bentonite, same as Kitty Liter.... make sure to use new Kitty Liter, otherwise the fragrance you get from placing hot steaming objects in used liter is a bit over powering......

[@HOWEES]

I actually buy kitty litter, it is 1/4 the price of "floordry" here in Fairbanks.

[@PolarisRider06]

14:39 mount an old/cheap 3 jaw lathe chuck to a wheel hub that you can clamp into a vice to give yourself a roll out wheel/fixture for stuff like this or for welding flanges on pipe

[@petersipp5247]

At one machine shop I worked at...the cast iron drum was 14" in dia. & had 6" high walls. It was so thick I had to preheat with a torch in each hand before it would take the yellow brass filler metal. When the cast part is small enough to sit in my trucks cab...I put the part in the cab. Then the sun warms up the whole part. When the cast iron part(s) are small & can be stick welded...preheat them in the cab too. When the yellow brass filler wire has no flux on it...put the flame on the filler rod then dip the warmed rod in a can of borax. The borax sticks too the filler rod.

[@ypaulbrown]

hello John, cheers from an old brazer here in Florida, Paul

[@TheAyrCaveShop]

Spot on ! in all respects ! Well Done.....

[@jamestregler1584]

And it's still an ART 🎨

[@ypaulbrown]

I tend to place my valves at 90 degrees, neither up or down.....but it all depends on what I am doing, one of the great parts of using a torch you are not limited to where you put the valves....

[@Doichable]

Also worth mentioning, not all cast iron/ductile iron is of the same quality. I've had some parts with so much carbon content that it wasn't even possible to get to the required brazing temperature without the part starting to disintegrate even before getting to the soft glow. Have had hit and miss with brazing submersible pump casings' for example.

[@ypaulbrown]

John, at 28:00 or so you mention the zinc goes away with low fuming bronze rod, when Tig welding, that zinc boils at 1665 degree F....and the Tig arc is over 10,000 degree f... Nasty stuff for sure.....and makes for a really bad Tig braze..... of course, when Tig brazing, you are not melting the base material, you are only flowing the Bronze on to the base and molecular attraction , [not sure of the exact term] is bonding the part together..... like super duper super glue or epoxy...... so Kids, do not melt the base material when brazing, unless you are brazing the same material as the filler, then you are no longer brazing, you are fusion welding.....

[@ypaulbrown]

when doing a repair with broken parts and building up material, if you get the base metal so hot as to be a bright red, you will be burning the base metal and your weld will fail.....the small sharp parts of the broken base metal can heat up very fast, something to watch out for....same goes for a sharp flange like John is dealing with... keep the flame away from that so the base metal does not get roasted... ..hope this may helps someone out there.....PB

[@tonyjones9715]

Thanks 👏👏

[@wesbrackmanthercenthusiast4695]

This is very helpful I have a 100-140 year old sawmill I'm working on getting running so I can use it that way I can make some funds to buy some machine tools since I want to start a horse drawn farm implement reproduction shop for my own equipment plus the local Amish communitys around me

[@bobbob8229]

Seems to be a good instructional video. Not too easy to see, but if you LISTEN-- you will learn.

[@nathandevine552]

Have you ever heard of orange brazing glasses instead of the normal green ones i heard of them but have never saw them their supposed to let you see the puddle better maybe someone was pulling my chain

[@bobbob8229]

People might not realize what's going on with the brazing Rod extending. (he's letting the rod stick to the puddle, then joining on a new piece) 😊

[@TobeWilsonNetwork]

With the oxyacetylene torch is inhaling that nasty tin oxide stuff a concern or are you staying below its vaporization point?

[@HOWEES]

It's zink oxide, you need some, so you don't have to take zink pills for health ! I try to not get it that hot.

[@kimazbell460]

Don't know if it's right or wrong, but since I'm right handed, I always set the valves to be away from my hand so I can adjust the flame with my left hand easily. Anyone else do this?

[@joefalmo5528]

So maybe you guys could answer question for me. Why is it that when we have heavy brazing to do it always seems to be when it’s the hot time of the year, never during the winter?

[@HOWEES]

The farmer didn't want to fix the old spreader, until He tried to use it in July.

[@donniev8181]

Can we see you get it back to a usable product?

[@HOWEES]

We took some videos, but not a full set, this is the box it is for: kzbin.info/www/bejne/rJfLaaeEZ8udeMU

[@Blazefork]

What renders oil impregnated cast iron super hard when its welded?

[@HOWEES]

Lots of variables in that question, I will be covering this soon. Most likely it was welded cold, and the extra carbon from the iron increased the carbon content in the weld, along with a rapid cooling & it ends up with spots of hard iron-carbide.

[@Blazefork]

@@HOWEES Thank you..... your the #1 machinist on KZbin in my books..... keep it up! More I think about your reply it makes total sense, when we would extensively preheat to "boil" the oil out the results were better.

[@aldoblasigh7533]

What about brazing cast ion clinder heads

[@benjaminjordan2762]

It can be done the same as welding them, but there is no guarantee with cast iron. I do not and will not guarantee any welding work on cast iron.

[@HOWEES]

I have had good results with that, the last set I did were some old 289 HP heads, it is much easier now, as I have electric pre-heat furnaces. It was very hard when I used to use a rose-bud for the mass heating.