# Braze or solder broken cast iron plane sides?



## sploo (16 May 2022)

I've got an old #4 1/2 hand plane that has some sentimental value and I'm trying to restore it to an at least reasonable aesthetic condition.

Some of the side is snapped off and long gone (see pic):







I've seen many brazed plane repairs over the years, but always using (what I assume is) brass rod; and I don't like the obvious colour difference. If I were to get some cast iron and machine it to an appropriate shape are there silver/grey brazing rods I could use with a MAPP torch, or would a "normal" plumbing solder be strong enough to hold a new part?


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## okeydokey (16 May 2022)

Could you buy another body and cut off the side you need and then have it welded on.
Or if you bought a whole plane the unused parts Could be sold to get most of your money back


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## Bingy man (16 May 2022)

It’s possible plumbers solder would work but I think your problem will be the steel will will get far too hot for it to work. Solder is designed for copper / Tin etc which heats up to temp quite quickly therefore it’s easy for the solder to run. Brasss rods have a higher melting point therefore are more suited to brazing steel but yes the colour difference stands out . A weld however can be ground back with little or no visible evidence.


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## Dee J (16 May 2022)

A brass brazed repair could have a kintsugi vibe... Complete but tells its history Kintsugi - Wikipedia.


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## sploo (16 May 2022)

Bingy man said:


> It’s possible plumbers solder would work but I think your problem will be the steel will will get far too hot for it to work. Solder is designed for copper / Tin etc which heats up to temp quite quickly therefore it’s easy for the solder to run. Brasss rods have a higher melting point therefore are more suited to brazing steel but yes the colour difference stands out . A weld however can be ground back with little or no visible evidence.



Interesting. Can't weld it unfortunately as apparently welding cast iron is quite difficult, and with only a cheap gasless MIG welder (and no talent) I fear I'd make a right mess of it.




okeydokey said:


> Could you buy another body and cut off the side you need and then have it welded on.
> Or if you bought a whole plane the unused parts Could be sold to get most of your money back



Should be fairly cheap to buy some cast iron and mill it to shape. I'd feel like a right vandal destroying another plane


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## Bingy man (16 May 2022)

in that case could you have it welded by a experienced metal worker - there may be some on this forum that can either help you or suggest someone or somewhere you have it done for you -I guess there will be some risk either way to weld cast iron ( sorry previously assumed it was steel )


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## Fergie 307 (17 May 2022)

I am afraid there is no way you are going to be able to repair that easily. To weld or braze cast iron effectively you need to get the whole piece up to a good temperature. Something as thin as that will warp all over the place, so would have to be 're machined to get it flat and square afterwards. Personally I would just clean up the edges and use it as it is.


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## John Hall (17 May 2022)

It would braze ok, but would also look obviously repaired. You can get cast iron welding rods which would match the colour, but would need to be in the hands of an experienced welder. Expensive too..


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## OldGreyDog (17 May 2022)

Silver soldering a new bit on might work?


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## sploo (17 May 2022)

Yea, wondering about silver soldering as I assume the required temperature might be a bit lower? As that area would purely be a cosmetic repair it doesn't need to be that mechanically strong.

I do take Fergie's point about cleaning the edge up and leaving as is though. Not what I want to do, but certainly preferable to damaging it further with too much heat.


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## cerro (17 May 2022)

A TIG AC/DC welder would do it no problem I am looking to buy the cheapest one when I sell my MIG. IPtools TIG INV 185 AC/DC and looking on youtube it seems to weld all metals cast, steel, aluminium, brass, copper. It also has a built in stick welder for thick steel. But anyone with a TIG will do it for you.


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## OldGreyDog (17 May 2022)

sploo said:


> Yea, wondering about silver soldering as I assume the required temperature might be a bit lower? As that area would purely be a cosmetic repair it doesn't need to be that mechanically strong.
> 
> I do take Fergie's point about cleaning the edge up and leaving as is though. Not what I want to do, but certainly preferable to damaging it further with too much heat.


Silver solder will likely be a better colour match, but its plenty strong enough. Top level lugged type bicycle frames were silver soldered when very thin wall tubing was used. Reynolds 753 tubing had to be silver soldered and frame builders had to be licenced by Reynolds before they were supplied with that type. If its strong enough for pro bike riders frames…


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## Vann (17 May 2022)

sploo said:


> I've got an old #4 1/2 hand plane that has some sentimental value and I'm trying to restore it to an at least reasonable aesthetic condition...
> 
> ...I've seen many brazed plane repairs over the years, but always using (what I assume is) brass rod; and I don't like the obvious colour difference. If I were to get some cast iron and machine it to an appropriate shape are there silver/grey brazing rods I could use with a MAPP torch, or would a "normal" plumbing solder be strong enough to hold a new part?



1. Applying a lot of heat to thin cast iron risks distortion - but can work, albeit sometimes requiring some surface grinding to true things up.

2. I doubt soldering would work for more than 5 minutes.

3. Silver soldering may work, but will have a colour difference.

4 Brazing (using brass rod) will work, but as you say has a very obvious colour difference.

5. Cast iron welding will probably give the best result, but requires the most skill (= cost).

However, here's a pikkie of my three "go to" planes.






The nearest is a modern (~2010) Clifton No.3. 
The next is a "warfinish" Record No.04ss. As you can see it has a chunk off the far side - but it's a great user - a favorite.
The last is a Record No.05. This has a brase repair - but it does everything I ask of it.

Being a bottom feeder I've bought a number of planes with repairs. Probably in 50% of cases the repair didn't go well and the planes are good only for parts.

A plane in mint condition is nice - but it's not a necessity. The missing wing on your plane is just a battle scar and, assuming you didn't break it, it's part of its history. Consider tidying it up and using it as it is. 

Attempting to repair it may make it look nicer - but equally it may distort it, ruin it, and/or cost you more money than the plane is worth.

My tuppence worth.

Cheers, Vann.


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## sploo (17 May 2022)

I've repaired/restored tens of old planes over the years (there should probably be a Planeaholics Anonymous for people who can't resist buying and fixing "lost dogs" ) but I've never tried brazing or soldering any parts of a broken plane sole (that's always been my red line for buying one). However, this plane belonged to a great grandfather - hence the attraction for trying to fix it.

I've ordered some (what I understand is) decent quality silver solder and flux, so I'll get some scrap cast iron and see how it goes before I get a torch near the plane.


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## hawkeyefxr (17 May 2022)

I have welded cast iron a little years ago, arc weld. It would need some pre heating then welding. To weld it straight off can cause stress and possible cracking later as it cools.
Cast is 'dirty metal so i would say silver solder will not take very well as silver solder likes the suraces quite clean.


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## John Hall (17 May 2022)

Soldering cast iron with silver solder. | Model Engineer







www.model-engineer.co.uk


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## Fergie 307 (17 May 2022)

hawkeyefxr said:


> I have welded cast iron a little years ago, arc weld. It would need some pre heating then welding. To weld it straight off can cause stress and possible cracking later as it cools.
> Cast is 'dirty metal so i would say silver solder will not take very well as silver solder likes the suraces quite clean.


that's why you need to get it pretty hot all over, to avoid stress around the repair, which will cause it to crack later. Your best bet would be to get it up to a good temperature using a Mapp torch, then whilst maintaining the temperature with the Mapp, use oxy acetylene to raise the temperature at the repair site the extra bit for your brazing rods to work, or preferably weld it. You can get specialist rods for stick welding cast iron and these are very good for this sort of small job. After making the repair put it in a bucket half full of dry sand, then fill up with more sand on top. This will stop it cooling too quickly, if you can heat the sand up as well so much the better. Leave it until fully cooled, then you may need to machine it to get it flat and the sides square. My concern would be that something this thin might warp to the extent that you would need to remove an excessive amount to get it true again. Repairs I have done on thin stuff like this have mostly been decorative items where being absolutely true afterwards isn't especially important, they can distort quite a bit. I suppose you could clamp it to a section of heavy steel plate or channel to help keep it true during the repair, although I have never tried this.


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## Torx (17 May 2022)

cerro said:


> A TIG AC/DC welder would do it no problem I am looking to buy the cheapest one when I sell my MIG. IPtools TIG INV 185 AC/DC and looking on youtube it seems to weld all metals cast, steel, aluminium, brass, copper. It also has a built in stick welder for thick steel. But anyone with a TIG will do it for you.


I’ve got a Tig and I’m not doing it 

Joking aside, having the equipment and having the experience and skill to make a good repair on something like that are two different things, especially when it comes to Tig which is a steep learning curve. 

What about cutting the other side off too and making a pair of brass sides for it, screwed or brazed in place?

I think whatever you do would need a bit of machining afterwards.


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## TFrench (17 May 2022)

Personally I'd leave well enough alone. It's part of the story of the tool. 
And @cerro , I wouldn't attempt that with my tig either. Too much chance of killing it for good.


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## KeenToLearn (18 May 2022)

You can get "cold" arc welding rods specifically for cast iron. Trick is just to do a bit at a time so it doesn't get too hot and distort. Not hard to use if you have used an arc welder before I can assure you


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## sploo (18 May 2022)

I only have one of the cheap gasless MIG welders (and a level of talent with it that needs a grinder and paint afterwards), so I assume trying that would be a really bad idea.


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## Setch (18 May 2022)

I'm sure someone on here, possibly now decamped to the a different place, used to regularly post work in progress photos which showed a no.4 with a brass repair plate screwed/riveted across a crack in the casting. It looked a bit Frankenstein, but was his goto plane.

Edit - here you go:



https://cdn.imagearchive.com/ukworkshop/data/attach/18/18169-Repaired-no.4.jpg



A forum search for "AndyT plane repair" turned this up.


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## Threadedpipe (18 May 2022)

Cast can be welded using a cast iron suitable rod on a stick welder mig welding on cast I have done but u have to control the cooling process with oxy acetylene to stop weld fracture far from easy to do


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## John Hall (19 May 2022)

If it has sentimental reasons for keeping, I’d definitely leave it to a professional or you could end up with a piece of scrap


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## Marischal Ellis (19 May 2022)

It may be possible to put brass dowel pins (nails) in to the plane and 'new' shaped side piece of steel /iron and join the scribed meeting edges using a thin line of metal weld type paste. Best not to do too much as it becomes what is or was not. Total restoration is not best. Flat planing would be OK. This is done on m/cycle side-valve heads. A honest repair.
Best wishes to all.


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## --Tom-- (19 May 2022)

If you made the missing piece from brass too and then brazed it on it would show the old vs the new in an honest way rather than look like a crack full of braze. Would have a higher chance of success and look good too


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## sploo (19 May 2022)

I have considered a JB Weld style epoxy to "glue" a new part on (instead of brazing or welding).


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## Spectric (19 May 2022)

Torx said:


> especially when it comes to Tig which is a steep learning curve


The hardest thing about TIG is keeping the tungsten gap constant and feeding the filler rod in which is like a dipping motion, much easier if you have gas welding experience. TIG is the ultimate welding process, all positions, any direction and so easy to join thin gauge material to much heavier gauge so a process worth the practice. You also want HF start and cleanliness, acetone is a great cleaner for TIG welding and don't wear heavy welding gloves, just lightweight gloves and if using a watercooled torch then wrap the cables round your arm for added support.


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## rafezetter (20 May 2022)

I've been meaning to repair a cracked chipped off rear corner of a #5, by smoothing off the rough edge then adding some brass soldered on and then drill and tap some brass screws, then file off the head - all of which is a bit fiddle hence it still being on "round tuit" list - I'd be interested to see your repair.


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## Candooman (6 Jul 2022)

sploo said:


> I've got an old #4 1/2 hand plane that has some sentimental value and I'm trying to restore it to an at least reasonable aesthetic condition.
> 
> Some of the side is snapped off and long gone (see pic):
> 
> ...


My brother, before he passed, was a reasonable welder and he managed to weld a broken cast iron coffee grinder handle back together using a technique he called sif bronze welding, or at least that’s what it sounded like. It was very successful and the grinder is in use to this day. Sorry, can’t ask him for any further details!!


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## sawtooth-9 (23 Jul 2022)

You can weld cast iron, especially with modern techniques.
However, the old principles still apply - GENTLY heat the whole piece, weld and then ensure a SLOW controlled cooling. This used to be done by covering the welded piece in VERY hot sand and allowing it to cool as slowly as possible.
Cast iron is a crystalline material, easily subject to crack development under uneven thermal changes.
Brazing is easier because the heat required is less and the thermal stress is less - but visually - and for strength _ it is inferior.
It's why iron castings were buried in sand or hot earth, sometimes for years - to relieve stresses and allow the correct crystal structure to grow. A common practice for railway wheels and good quality lathe beds.
That's why it's best to get the weld done by someone with experience.


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## sploo (23 Jul 2022)

I bought some (apparently appropriate) silver brazing rods, but like so many other projects I haven't had time to get back round to it yet. One day... one day


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## hlvd (23 Jul 2022)

Broken planes used to be repaired by brazing.

The plane would be perfectly functional but you’d have a bronze coloured lined where the break happened.


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## sploo (23 Jul 2022)

hlvd said:


> Broken planes used to be repaired by brazing.
> 
> The plane would be perfectly functional but you’d have a bronze coloured lined where the break happened.


That's ideally what I want to avoid - though I accept it may be easier said than done.


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## TRITON (23 Jul 2022)

Grind it right down then put it on ebay as 'specialist super rare plane oddity' with a starting bid of £200. The plane collectors will go mental for it.


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## hlvd (23 Jul 2022)

sploo said:


> That's ideally what I want to avoid - though I accept it may be easier said than done.


That was done by time served welders, it’ll be strong and functional, you’ll have to turn the repaired side towards the wall if you want an ornament though.


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## Fergie 307 (24 Jul 2022)

Whatever method on use you will not get an invisible repair. If you get it welded the repair will still be quite obvious.


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## happymadison1978 (24 Jul 2022)

I might be alone in this but I think a well brazed repair could look quite cool- it’s part of the plane’s history/function


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