Aluminium “Welding” Rods
 

I have been getting occasional adverts for some “welding rods” that are used to weld aluminium and I was wondering if anyone had used them. They are marketed by a company called Millionus. They appear to be really easy to use so, as I have couple of pannier lids that I need to get welded up, I was wondering about getting some but if they are rubbish then I will get someone to weld them up for me. Yes, I am so sad that I have made my own panniers - it has been good fun actually.

https://www.millionus.co.uk/products...30961102159923

They seem too good to be true which makes me think that there is a catch somewhere - they aren’t very expensive and I guess they could be used to fill holes on crankcases. If no-one has used them I will get a set and do a review - maybe even do my own video.

I'm sure there's some people on here who have a lot of welding experience and for whom these things are second nature. I'm not one of them, but I've done welding courses in the past and become passably familiar with arc, gas and tig (using someone else's decent equipment) and pretty good (for an amateur) with my own mig. I've even tig welded aluminium bike bits (with the instructor leaning over my shoulder!), but I can't do anything at all with those aluminium 'welding' rods.

I've tried several times to repair stuff with them without success and there's a few projects that could do with their help right now. I have a load of rods and other bits - including the instruction DVD - sitting in my tool chest waiting for the day when I figure out where I'm going wrong (probably via a good youtube video). I suspect my heat source isn't good enough but that costs money whereas the rods are cheap. The feeling I have is that the heat margin between success and disaster is too close for comfort.

Give it a go and video it - I'll watch it, but practice on something of no value first.

Does this mean that you have tried them but to little success? If that is the case And you think that it is the parent metal temperature that is critical then I can see a case for getting a cheapish laser thermometer - I am thinking of getting one for work anyway but this would clinch it.

I have every intention of getting good first before doing something that matters.

Yes, I've tried a number of times to get the rods to 'weld' but not managed it. It's been a while now since I last tried it but from memory there's a number of reasons why that may be the case - I may have useless technique, I may not have cleaned everything sufficiently, I may have been getting / able to get the workpieces hot enough or the alloy I was trying to repair may not be suitable. Again from memory, the last thing I tried it on was some cracked Kawasaki alloy manifold clamps. I couldn't replace them (unobtainable) but I didn't want to ruin them either.

The rods are more like high temp soldering than true welding and it was getting them to melt and run into the alloy that was the issue. Like normal soldering you can't just blob the stuff on, it doesn't take. The alloy needs to be clean and hot - much hotter than normal soldering but I was worried I could overheat the whole thing and just end up with a puddle on the bench. Aluminium doesn't give you any warning - like glowing red etc, so you have to use other methods. I have an I.R. thermometer but I'm not sure it goes high enough (?).

It was on my list of things to revisit but, prior to your post, fairly well down it.

Ally welding is a pretty skilled process, as BoB says, you don't get any warning when it's going to melt, it just goes, so you need to know how much heat you're putting in or you'll either melt holes in it or just blob metal on top which will be useless. Another complicating factor is that aluminium oxidises very readily so if you don't weld it in an inert gas atmosphere (Argon is the usual gas shield) you stand a good chance of ending up with a spattered lump of alumina instead of a weld. Finally there's the Heat Affected Zone (HAZ) that develops where the recrystallised grain structure meets the original grain and that's where it tends to break, adjacent to the weld rather than through it. I'm not a welding expert but I believe if you preheat the weld zone or post heat treat the entire component you can avoid a lot of the HAZ problems - but again it's a question of knowing how hot and how long.

The thermometer I have looked at goes up to 550C and the melting point of aluminium is around 660C but the rods talk about a temperature of less than 480C so there is a decent amount of wiggle room there. I suspect that it is a two person job - one to heat and monitor the temperature and the other poised to apply the rod. The thermometer is a laser infrared job so non-contact and instant - the trick I guess is to get the temperature just right across the workpiece.

Aluminium oxide starts to form quickly at around 450C so the final 30C gain needs to be done quickly. The other thing is making sure that the aluminium doesn’t anneal - in my application for my pannier lids this is not a big deal but other applications may not be so forgiving.

That'll be a posh thermometer - mine only goes to 380C. You don't need to get the aluminium up to melting temperature for the rods to melt and flow. The instructions say there's a 200+C 'safety margin' between the temperature you need and the aluminium melting, the idea being that once you get the ally that hot the rod will flow onto it.

You can't melt the rod in the flame you're using as the heat source and 'flow' it onto lower temp ally - it won't do that, it just balls up or runs off. The problem is that in a hot flame that 200C margin can vanish in seconds and there's no way of telling how close you are. Maybe with a decent IR thermometer it'll work but last time I tried it I didn't have mine and it was all guesswork.

I saw this video some time ago, and thought he did a very good review:

I'm going to have to have another go at this sometime soon. I checked my rod supply yesterday and there's half a dozen half used ones as well as a load of new ones, so enough to try again. I don't want my ineptitude to colour this conversation though so it would be great if somone who has managed to weld / braze / solder with them to chip in.

An interesting review. So it has its place - temperature control is clearly a key factor as is preparation.

Agree, it's clearly not "easy" like grabbing an old arc welder and sticking a couple of pieces of steel together.
Perfect Prep has always been the biggie from my limited experience with aluminum welding.

"Alumafix" welding rods...
 

Technically, these rods do not "weld". A general definition of "Weld" is to melt two pieces being joined along with the deposition of welding material (ie the rod or wire) and the result being the two pieces fused together.

What you are showing us there is a form of "soldering", where the two work pieces are not melted or fused, the only thing that melts is the rod itself, that is melted and flowed and adhered into the joint.

So What? Will it hold? Yes.

Since the material in the rod has a lower melt temp than the two pieces of aluminum being joined, the "weld" material is obviously a different metal than aluminum. The weld metal would probably have a different coefficient of thermal expansion/contraction than the aluminum pieces, so repairing a crack in an aluminum head or block that sees high stress at a wide range of temps will probably crack and fail.

I initially bought a few rods of it to repair a punched-in oil-pan on a VW ALH Jetta. I got mine off e-bay for like $3. The 2.5cm triangle shaped chunk of oil pan was knocked out and missing. I fashioned a patch from 1/8" thick aluminum plate. Wire wheeled both pieces to a clean surface, not shiny. Heated both pieces up with hand-held torch with MAPP gas, and wire wheeled again. Then held together in the press, using a big 3/4 drive socket on the inside perimeter of my repair area and a small socket on the outside in the middle of the patch. Not tons of pressure, just enough to hold it. Watching the videos, you can see that one of the things that happens is the heat applied by the torch is transferring away into the rest of the parts, so your torch has to be able to add heat faster than it transfers away. If clamping parts together, be aware of the heat transfer capacity of your clamp, a chunk of steel with lots of contact area will take away a lot of heat. In my case, the perimeter-edge of a socket is round-ish, and the actual contact area is quite small, so heat transfer is minimal. That was several years ago, and I still see that Jetta driving around, and the owner tells me the oil-pan is still holding. Fixing the oil pan was a waste though, replacement oil-pan from a self-serve wrecker is like $20.

The other thing I've repaired is a stainless steel ladle or dipper. It was a stainless steel cup with a handle-strap of stainless steel spot welded to the side. The spot welds had let go. Its a vintage useful/ornamental item that hangs on the woodstove that we use for ladling hot water out of the heater tank. I carefully ground the surfaces, held them together, and applied the alumafix solder, and its holding well.

So to repair the pannier lid, I say have at it. The danger is that the pannier lid is super-thin, and applying heat may distort it forever. The other possibility is that the lid is not actually aluminum, but some alloy that melts lower than you expect, in which case you will be warming up the pieces to apply the solder and your pannier lid blobs onto the floor.

As with any solder/braze process, surface-prep is key to success, clean, and microscopically rough so the material can adhere. As mentioned, your torch has to be able to add heat faster than heat transfers away. A standard hand-held propane torch may theoretically reach the melt-temp of the solder, but will lose the heat transfer race. You pretty much have to use the more expensive blended MAPP gas torch.

Good luck!

Yeah I think he covered the main points pretty well. It is soldering not welding, since there is no melting of the parent metal, and that makes it a process that needs to be a lot less closely controlled. As he found, it isn't as strong as the parent metal, it's only as strong as the solder itself, and is dependent on getting a really clean surface to bond to - but still, it's not a bad performance at all.

As he says, it's definitely not something to use on anything structural like a frame, but for some applications it *may* be a viable get-you-home. And for non critical items a good one for the more creative to have in their shed ;)

As an aside, when I was racing years ago I had a Mk4 Seeley, and I got a spare tank made by the same guys down in Dartford who built the originals for Colin Seeley. They gas welded all their ally tanks, and the workmanship was superb. I never understood how they did it, given the propensity of aluminium to oxidise when heated in air, but I wonder now if they soldered it using the same sort of stuff as this. Whatever they did, it certainly worked and didn't suffer any distress despite 10 years racing including the Manx GP.

Interesting.

Grant's video pretty much shows it's pros and cons.

Great for DIY and i'm sure plenty good enough for panniers.


I think i'll stick to my TIG welder though.

The rods have arrived and they seem pretty easy to use. Surface prep is important as has been rated by others - the kit I bought cam with a toothbrush sized stainless steel wire brush - the brush is very abrasive on aluminium.

Points to note so far:
The size holes you can fill is limited to about 8mm diameter in my very limited experience and as you move towards 8mm the thickness of the covering gets thinner so ends up more like a film towards the bigger holes so if pressure is involved for big holes forget it. I think I would braze a patch of aluminium over the hole if bigger than, say, 5-6mm.

If I was to be putting a patch over a large hole then I would prepare the surface around the hole and the the patch. Apply the rod to form a “puddle” around the hole and then do the same thing for the patch contact area. Finally heat the patch and hole area to get the puddles liquid so that the patch can be placed over the hole sealing it.

Ensuring the piece stays still during the cooling process is important as the filling metal stays liquid longer than I expected. My fault entirely.

For a butt joint it is better to have access to both sides of the joint to put a “weld” bead down both sides.

You can easily make smooth looking joints easily and they seem to be relatively strong - it is NOT welding so it is weaker but it could be a simple remedy to carry out a bodge repair until such time as a proper repair can be done.

The rods are lightweight and don’t take up much space so I can see myself taking some on a trip - the heat source can be from a plumbers torch so should be simple to obtain locally.

I still plan on doing a video but that will have to wait for a quiet day at work and some time to prepare samples.

The rods have arrived and they seem pretty easy to use. Surface prep is important as has been noted by others - the kit I bought cam with a toothbrush sized stainless steel wire brush - the brush is very abrasive on aluminium.

Points to note so far:
The size holes you can fill is limited to about 8mm diameter in my very limited experience and as you move towards 8mm the thickness of the covering gets thinner so ends up more like a film towards the bigger holes so if pressure is involved for big holes forget it. I think I would braze a patch of aluminium over the hole if bigger than, say, 5-6mm.

If I was to be putting a patch over a large hole then I would prepare the surface around the hole and the the patch. Apply the rod to form a “puddle” around the hole and then do the same thing for the patch contact area. Finally heat the patch and hole area to get the puddles liquid so that the patch can be placed over the hole sealing it.

Ensuring the piece stays still during the cooling process is important as the filling metal stays liquid longer than I expected. My fault entirely.

For a butt joint it is better to have access to both sides of the joint to put a “weld” bead down both sides.

You can easily make smooth looking joints easily and they seem to be relatively strong - it is NOT welding so it is weaker but it could be a simple remedy to carry out a bodge repair until such time as a proper repair can be done.

The rods are lightweight and don’t take up much space so I can see myself taking some on a trip - the heat source can be from a plumbers torch so should be simple to obtain locally.

I still plan on doing a video but that will have to wait for a quiet day at work and some time to prepare samples.

So which one did you buy then? Maybe you could give us some tips about welding.:rolleyes2:

OK. Tips about welding with these rods.

1. Preparation is key
2. They have their place but not for something structural
3. I am rubbish at welding, these make me look good and allow an even line to be made. Sometimes, in my case - definitely not every time - so the tip is don’t ask me to do it for you
4. The rods could be used to cover over a small - up to 7mm say - hole but not to any great pressure.
5. I will use them to seal up the corners of my pannier lid - non-structural and could be made to look pretty good.
6. Powder coating goes over the top as if it were normal metal (which it is of course being an aluminium alloy)

I still have to edit the video I made but have yet to have any time to do it.

I'll look forward to the video as it sounds as though it went reasonably well for you -if a little hit or miss. What did you use as the heat source?

I used a gas burner we use at work for cleaning off hooks which have acquired too much powder coating - I have a powder coating factory. It would be fair to say it isn’t too subtle and that may be the reason I have been - as you say - a little hit and miss. I used that as it was to hand.

I do have a nice neat torch that is far more appropriate for most applications - it is similar to this one https://www.screwfix.com/p/rothenber...ignition/82945 - when I do my pannier lids I will use that torch.

One thing that I should point out is that using too much heat affected the strength of the samples I used as the process annealed them softening the aluminium. Hopefully with a more delicate torch, and touch, the lids won’t anneal - this will mean having to get it right first time on each corner.

Having joined in Ted's 'Aye' thread and read about FB v. HUBB, I thought maybe HUBB needs a bit more traffic with bumped threads.

So I'll share an ancient anecdote about aluminium welding. (Or soldering I suppose.) Pass by if old stories aren't your thing...

At the 1970 TT (as a spectator) I had an 'incident' just before practice week started, the alternator cover of my bike slid along the road a bit, wearing a hole right through it. :oops2:


I was staying with friends and a couple of competitors who said, "No probs, take the cover off and I'll give you a lift to the Reynolds garage. Ken Sprayson will weld that up in a jiffy."

There was a bit of a queue, with competitors and mechanics with all sorts of stuff for repair. It was an education to see Ken repairing everything that was presented to him. Pretty much all steel stuff.

Then I offered my aluminium cover, with quarter-inch hole in it, the surrounds of which were very feather-edged, out to over 2-inch diameter.

"You lads don't half bring me some stuff, don't you!" he exclaimed.

I suppose he must have changed from acetylene to something else, and first 'tested' the feather edge to see how readily it melted, noting how the hole grew, spending a short while in deep thought. Selecting a rod (aluminium I assume) he set to, gingerly depositing blobs of ali weld/solder on to the feather edging. Sort-of playing with it to just melt bits of rod and a smidgen of feather-edge, growing the thickness until the hole was completely filled. Don't remember if he used a flux and definitely don't remember how he stopped it oxidising.

It looked a magnificent repair and he seemed very satisfied with it.
"Where did it happen?" he asked.
"Approach to Braddan Bridge," I had to confess.
"Don't do it again!"

As I turned to leave I was amazed at the size of the huddled queue that had been studying his artistic work.

A while ago he published his second book of TT photographs - he's quite a serious photographer.

The front cover carries a photo of - the approach to Braddan Bridge, with Mick Grant sweeping through. I'm sure there's no connection, but it's strange what coincidences occur in life.

His repair was long-lasting, it was quite a while before I fitted a new cover. And very sadly, I probably scrapped the old one that he repaired.
"What a stupid thing to do!" I thought when I first saw the front cover of his new book...

Comparison vid.
 

Some good info on this thread.
This vid might be of interest.
https://www.youtube.com/watch?v=fKIKsDfRAcs&t=623s

I ordered some more "welding" sticks from eBay - to be honest, they were rubbish compared to the ones I got last time. The temperature that they needed to melt was above the melting point of the material (aluminium) I was trying to join. I will be getting some more from the original supplier as they do what is expected. I was less than impressed by the two different sorts I bought off eBay- I know, get them from a known source.

The first difference between the sticks that I noticed is that both new (rubbish) ones (different sizes and suppliers) were significantly shinier than the originals which were a completely flat matt finish compared to glossy for the new ones.

It may be that the new ones will be fine with higher melting point materials (probably not carbon steel though stainless has been mentioned as a possible material it can join - yet to be tried by me).

When I get more of the original sticks in I will try to get some decent footage for a video and then find some time to edit the video such that it is too the point - the first attempt had a combination of poor camera work and far too long. The thing is that there is great potential for the sticks to be useful to me where I work and be small enough for me to slip a few into a pannier / tool tube to do repairs on the road (getting a heat source from someone else) - I just need to be sure that the sticks do what they say they will do - the second lots just didn't.

Aluminum is a rather complex metal that is difficult to heat treat. The most reliable welding method is argon welding. During welding, argon prevents aluminum from oxidizing by displacing oxygen. Before you do any work on aluminum, think about the quality of your welding machine. It will directly affect the quality of the welds. I bought my welder from this site https://ratemywelder.com/best-miller-welder-reviews/. For many years it has not let me down. If you want your work to last, then I advise you to choose a good welder intelligently. Fifty percent of the result depends on it.

Where are we with this one? Anybody actually tried repairing an aluminium casting with them? I only ask as I've got a hole in a carburettor float bowl to block up and all my 'easy' options (epoxy etc) have all failed.

I've seen a few YouTube videos of 'miracle fixes' but also a few where the casting melted before the fix worked. As my chances of getting a replacement float bowl (it's from a 51 yr old bike) are close to zero I don't want to put this one at risk. An expert might be able to do it but you need skill that counts me out.


https://i.postimg.cc/ydqJgpgq/D3S7656.jpg

Aluminium repair
 

I have used these types of rods.
No to fill holes. But to repair cracks in engine covers.
Like covers over generator, clutch, ignition.
On old bikes that were projects.

And it worked well.

I could get the cracks repaired.
After grinding and polishing, it looked ok.
The colour of the repair is not exact the same...
But it worked in the so that the covers could be used.
And looked good, but not perfect

Usually I would offer that you send that to me and I'd TIG weld it for you for the price of a beer.

But your bowl looks very pitted and crumbley. I would look for a replacement.

However, not easy in the classis bike world.

For that, I would do the same repair as a old fuel tank. With a brazing rod and MAP gas. Your bowl doesn't look like it would survive a TIG torch. Especially as it looks very porous. It would likely be deep contaminated with fuel and impossible to clean or grind down to virgin material.

Brazing rods are cheap and will work well on your carb. Look at videos on YouTube for classic fuel tank repairs with brazing.

Thanks for the info Ted. It’s not quite as bad as it looks in the photo - the angular lighting makes the pits look like craters - but the area around the hole does have a few marks. To get a hole something must have attacking the metal and where one hole has appeared others must be on their way. From where it is - down on one side of the bowl - I suspect the bike was left at an angle on the prop stand and whatever was in there has had plenty of time to act on the metal.

It’s a VM26 Mikuni so you’d think parts should be easily available but the current stuff is a slightly different shape casting so the new bowls won’t fit the old style body. I’ve been looking out for a second hand replacement for some time but nothing has come up, so trying to figure out the best way to repair this one is now where I’m at. There’s plenty of bodge methods but I’m reluctant to go down that route.

I’ll check out brazing on YouTube but its been a while since I brazed anything so a bit of practice probably wouldn’t go amiss.

Brazing is done at a much lower temperature. So easier for DIY and it's less stressful on the material. It's a capillary action. It was good enough for motorcycle frames before industrial welding became mainstream. It's the 'Go to' repair for thin or delicate materials. You could even lead/tin or silver solder that hole although brass would be better. Getting the material as clean as possible (lightly sand with a soft dremel etc) will yield the best results.

24hrs is long time, not only in the world of politics, but also in the worldwide search for ancient carburettor parts. After finding nothing for the best part of a year I've found one float bowl for sale and had the offer of another for free. So, when the first of them arrives, I'll rebuild the carburettor and get the bike running. I can then have a look at brazing the hole in the existing one without fear of getting it wrong. :thumbup1:

When I got the first batch of “welding” sticks they worked well and were easy to use taking into account that I am a ham fisted Luddite. As I practiced I got better. However, as I used them all up quite soon, I bought some more and they have been nowhere near as easy to use and the results have even somewhat worse than the first batch. They were from different suppliers so I would say if you get some be prepared to hunt around for a good source and don’t use the first of a new batch on an important job.

The first batch I used to fill holes up to 5mm diameter successfully, the second batch I had to melt the metal I was meant to be welding together before the stick melted so no use whatsoever.

Is there an identifiable difference - a different supplier or name or something, or do they vary at random? There seems to be an almost infinite number of suppliers with only the word before 'weld' changing - Lumiweld, Alumiweld, Technoweld, Easyweld (or was that EZweld?) Durafix, HTS-2000 etc. They all seem to be claiming the same thing but it would seem they're not all actually the same product. How do you choose one over another?

epoxy ??
 

Sounds strange to me. With all types of epoxies and polyesters that are available. Some thin sheet to cover the hole from inside.With super glue. To support epoxi / polyester from outside ??

If you can repair fuel tanks, water pumps... why not carburetor ?

I think the first ones I got were Durafix - I am by no means sure though. I can’t even member if I git them through a Facebook ad or eBay. Visually they were a dull silver grey rather than the shiny silver that subsequent suppliers sent.

I only know the epoxies that are available to the general public, and probably not all of them. Some years ago I went into a car spares warehouse in Utah to buy some epoxy for emergency repairs on my glasses and they must have had 50 different sorts available. None of them were sold as suitable for spectacle repair (not surprising really!) and they wanted me to sign a waiver saying I'd bought the stuff I selected against their advice. :rolleyes2:

Whether any of them were sold as suitable for fuel system repairs I don't know but the easily available ones in the UK don't work. Over the last year I've tried blocking up the hole, patching over the hole, etc with a number of different materials - including polyester - and eventually they all leak and patches fall off. My latest attempt before recently finding a replacement float bowl was a stainless countersunk 1.6mm screw pushed through from the inside and sealed in place with JB Weld (+ a nut on the outside). That had survived a few days on my 'leak rig' but just about all the attempts last a few days.

Maybe petrol isn't what it used to be - well, I know it isn't as it's now 10% ethanol, but whether that makes a difference I don't know. And neither does anyone else I've asked including some well respected engineers on other forums. Or maybe epoxies, like paint stripper, have been so h&s sanitised that they no longer do what they used to.

Lateral thinking - finding a way round a problem - is a useful mindset to be able to call on if you end up in trouble on a long trip, and I'm probably as good at it as anyone. Any of my previous attempts to block the hole would have been good enough as a 'shade tree' repair and would have got me out of trouble if it had happened on a trip, but longer term you need something more permanent. If there is a petrol proof (as opposed to 'resistant') epoxy (unlikely with the mindset above) I'll be sure to get some but I've not found any yet. Fortunately I now have an intact replacement and the carb now works without leaking, but I'd still like to repair the original.

True. There are plenty of "chemical metal" repairs. And epoxies such as JB weld etc.

I've seen a lot of repairs done this way. Some have lasted. Some have not. They are BRILLIANT for emergency repairs. Especially on radiators, crank cases etc. The trick with those (like most things) is preparation. Clean materials. Contaminants removed (grinded down) and cleaned up nicely. And when you've got to that stage it seems daft to use an epoxy when you could have a permanent brazed or welded repair done. Assuming you're in the position to do so.

I wouldn't use an epoxy or metal putty on a float bowl. You're fighting against the highly potent solvents in the fuel and also against gravity. And the risk of peeing fuel out of your carb when it fails is not a small one. I also wouldn't want any kind of epoxy or putty failing inside my carb either. When they fail, they crumble and break up. And that just screams 'BLOCKED JETS' to me.

@backofbeyond.

If you're in the UK, you're welcome to send me your float bowl and I'll see what I can do with it on a wet winters Sunday afternoon. I have a high-tech AC TIG welding set up and also a decent brass brazing set up along with all sorts of sanders, grinders etc to clean up small parts. No guarantees of success but perhaps worth a try. :thumbup1: