Welding fins on barrels

Hi Ian. Although cast iron fins can be welded, it is a simpler job to braze them on. I don't know where you live but down here in East Devon, Dave Massam (Colyton) said he would fix (by brazing) my cast iron head and barrel, but have yet to find time to get them to him. I guess welding would ultimately be stronger, but one would have a more difficult job grinding the weld line smooth as to make it invisible. Also, as far as I know, welding may require the whole barrel to be pre heated to a very high temperature before the welding is done. However if someone knows an expert that can do the work by weldingand finish with an "invisible" mendand at reasonable cost I would also be interested.

Les

Les is right, brazing is definitely the way to go. Not many people realise that you can braze almost anything to anything! Even ceramics! For cast-iron barrels you can use steel or brass for instance. The cast-iron bits I've seen on barrel repairs looked aweful - worse than the broken fins did! People will talk about differential expansion but it's only important for large areas. File down the raised brazing marks then paint it black! Or, even better, get it stove-enamelled like wot I'm going to do!

Cheers, Lionel

Previously wrote:

I have now had a go at brazing sheet steel fins on to a cast iron barrel using a MIG welder and brazing wire, and it is possible. You have to use argon gas, and start by grinding a generous chamfer on each of theedge's which you willfill with braze (braze will not flow likesilver solder),start by tagging the bits in to position,

I found that a run can be made where the iron fin and the steel one are adout the same thickness, and well away from the centre where the iron is thick, try a run here and the braze will crack when it cools (differential expansion I think), so I use lots oftags to keep the heatto a minimum, I thinka welding man willcall it monkey nut welding because that what it looks like, but what the hell you can grind it off smooth.

I now have the two fins back on the barrel and no one will know they were ever off.

Next problem is where can I get a setof rings from for less than £54 ??

Try Ebay, there are a lot of dealer selling many items on there for early and late Norton Models, not sure how much as I have not wanted rings for my restoration 600 yet

Previously wrote:

Hi Lads Thanks for your input, but because of the a mount of welding or brazing to put the fins back (for some reason the two top, rear fins have been surgically removed, some say it was to get a fixing from one side of a fairing to the other!!!) all the professionals I have spoken to all suckair through there teeth and say that's a big job it's going to cost and you will need a re-bore after, not what I want as it is on a standardbore and in excellent condition.

So after a look around the net I came across an artical telling how to braze cast ironwith a MIG welder, so I'm going to get me some brezing wire wire (at great cost) and make two new fins from sheet steel and have a go, on an old barrel at first, I willlet you know how I go on.

Wish me luck Ian.

hello ian your all mad men You cannot Mig weld steel to cast iron you neen the rigth cast iron and and the way to weld cast fins on is to stuff wet casting sand in ot the barrel and all around it too but the area you working clear of sand then you need cast welding rods 0.8 and about 90 amps on your welder and good eye and stead hand and lots of experance in welding That why it cost so much ? I know I have welded cast iron its not that easy to weld ? its got to be the right tempture to weld it ? but good luck anyway ?

hi i am a welder and yes you can weld the fins om with a mig but hear is the bad bit you will have to clean up all the erears to be welded with a file ig you do it with a grinder you will force carbon from the wheel in to the serfice that you are going to weld

you can also buy cast rods for your ark welder

before welding line the borse with a damp cloth and fill with wet sand this will help keep the bore cool

i have used this metherd on lots of diferent barels with grate suckses

eny way hope this helps and sorry for the spelling im pislexic lol