Mower petrol tanks.

[Retired]

Hi,

Over the last few months I've fully restored a Suffolk colt petrol mower; learned metal spinning and Tig welding.

I restored the mower but after lots of work stripping and repainting its petrol tank found the bottom of the tank to be pin holed much to my annoyance. For our wedding anniversary and my birthday last year Bron kindly asked of me what I would like as a prezzie. I've been arc welding for over 55 years having my own industrial oil cooled 180A arc welder and although I'm well aware of Mig & Tig welding have never tried these so Bron generously bought me one of these to play with;

https://www.parweld.co.uk/shop/machines/tig-inverter-machines/xtt-202p-acdc-pulsed-tig-inverter/

First thing to happen was the welder exploded but Parweld were wonderful and three weeks later the welder was in full working order; I wanted to make a new petrol tank but from aluminium and to a different style than the original; I had a lot to learn. Tig welding aluminium proved a great deal more difficult than I ever imagined; I practiced and practiced running bead after bead then more practice welding the five kinds of joints.

My plan was to make a tank with domed ends and this involved metal spinning which again I've known about for over half a century but never attempted. I did all the research and obtained the tools and correct grade 1050 aluminium; I have an heavily modified Graduate woodturning lathe suitable for a bit of metal spinning so I spun two tank ends and for the main body used ready bought aluminium tubing.

The dire weather was fighting me throughout; constant rain and very low temperatures to contend with but slowly I made positive progress. With the tank sections ready I could now have a go at Tig welding and the outcome is a new petrol tank to my own design.

About a week ago pleased with the new tank I wondered if I could now copy the original tank which was a very difficult shape. This original steel tank is pressed out in two sections a top and a bottom joined by a welded flange. After a lot of thought I decided to do away with the flange and make the tank out of three sections. I've never attempted working with aluminium and I was using 2mm thick sheet. My plan was to make a wooden plug this a copy of the tank shape but I didn't have a thick enough piece of wood so I glued two pieces together giving the size needed. A card template of the tank end shape was cut out and the shape transferred to the plug; after being cut to profile on the bandsaw the ends were reduced to shape.

The middle section proved easiest to form around the plug then Tig weld. The two ends though were something else; I only have general metal working tools with no panel beating hammers or dollies so it was a case of making use of what I had to hand. The shape of the wooden plug proved impossible to hold in order to form the ends so more thought was needed. 18mm thick MDF was chosen and I made a pair of "handed" plugs; now I could nip the aluminium in the big engineering vice sandwiched between plug and backing piece; the first end I beat into submission but it was extremely difficult although with an aching arm I won in the end. For the other end I adopted "cut and weld" cutting wedges out then beating over; very crude with the hacksaw; tin snips and hammer but it proved a lot easier and quicker and obviously mean more welding.

As I type this tank is almost completed; the new filler neck and cap arrived today and when I collect more argon gas I'll weld the neck in. I'm delighted with both tanks; the first tank I left the welds as they were but the cloned tank I brought the welds down flush.

I've taken months to reach this stage but since buying the scrap mower I've learned metal spinning and Tig welding both in aluminium.

Kind regards, Colin.

The first tank with metal spun domed ends.

The original tank with card template.

First attempt ever at metal forming.

It worked and here is the middle section.

I wanted plenty of weld thickness because it was to be dressed flush and I wanted to do it in one go.

A lot of work but well worth it and two new skills acquired. The filler neck has arrived and will be welded in and a tap installed to the bottom. Not bad to say I used bits of timber and MDF as plugs. Now I know the basics I can improve on future projects.

The tank ends; the bottom beaten into submission but the top one cut and weld making it easier and quicker. Both tanks are a success and I'm delighted with them.

 

[Ian]

That is fantastic @Retired! A very satisfying result indeed . I look forward to seeing the final product - the mower is going to look great with this and the new coat of paint.

 

[Retired]

Hi,

Many thanks Ian; I'm finding making these petrol tanks to be very interesting indeed and a nice challenge they being something I've never previously attempted. I restored the mower months ago and only after completing it and fuelling it up did I find the original petrol tank to be weeping hence my interest in making a new tank from scratch just for the fun of it but once I started it took over my life.

The mower was scrap at £20 when I bought it and although I already had two petrol mowers couldn't resist this to play with.

Here it is fully restored with an ugly plastic temporary petrol tank fitted just to get it running.

Restoring this mower was a very satisfying project reminding me of my motorcycling days when I used to restore motorcycles; a project like this doesn't cost much in monetary terms it's mostly down to getting dirty hands and having fun.

It sure was scrap. Here's the clutch drum.

After a quick spin in the lathe it looks much better; I used my Graduate woodturning lathe to do this to save messing up my expensive rare engineering lathe.

The condition of the inside of the engine was even worse than the outside; no compression due to a seized exhaust valve; a full decoke and valve grind sorted it out.

The same valves now back in service after spinning on the lathe; the exhaust valve is badly pitted but there's now lots of compression.

Here are the tanks so far; the one right is the original which I can repair by welding a patch in. Today I set up the new filler neck and cap on the left tank; I'll Tig weld the neck in once I obtain a full cylinder of argon gas. Both new tanks still need mountings welding on but are now mostly complete and they don't leak.

Kind regards, Colin.

 

[Retired]

Hi,

The original shaped new tank is just about finished only needing drilling and tapping for the new tap. The filler neck; mounting and thicknessing piece are all now successfully welded on.

Mounting awaiting welding.

This mounting sure is a strange shape so in order to copy it I made a card template then used this to draw around on flat aluminium sheet; it was formed around steel piping by hand to give the required shape.

The filler neck welded on.

Mounting now welded as is the thicknessing piece for the tap this still to drill and tap. When or if the weather improves I'll rub the tank down and spray it green to match the mower.

Kind regards, Colin.

 

[piglet11]

Hello Colin
That looks outstanding, a real labour of love or vice versa.
I did one once but nothing close to that standard.
A "proper" mower, well before the invasion of the plastic mowers.
I have got a Ransoms Ajax push mower waiting for some TLC , when time allows, but the list just keeps getting longer........

 

[Retired]

Hi,

Thanks piglet; much appreciated. I can recommend these projects as they are most interesting with something useful at the end. The downside was the cost because for a home workshop Tig welding is expensive with Tig welders at around £1,000 for a reasonable starter then the consumables like argon gas quickly bump up the cost so £1,600 is quickly reached but it's not about money which I can afford it's about leaving my comfort zone to try something new. Tig welding aluminium to a complete novice is very difficult; I've been arc welding for over 55 years but found Tig welding more difficult than I expected.

Tig welding aluminium uses a lot of pure argon gas and I quickly used 3 hobby 9L low pressure cylinders costing in total over £200 then I opened a BOC hobby account and now use BOC "Y" 20L high pressure cylinders which work out a lot cheaper for anyone really wanting to get into Tig welding; I've just paid my BOC invoice and have collected my third cylinder this third cylinder has cost £69.59 due to BOC now charging a delivery cost to the BOC agent I collect from but it's still a lot cheaper than the 9L low pressure cylinders even taking into account the yearly rental cost which isn't returnable so the more BOC gas used the better the cost.

The last time I fired the Colt up petrol was running out of the carb; I had replaced the faulty float and needle in the carburettor because the float had worked loose on the needle; I now think the same thing could have happened with the new float and needle but it's been bitterly cold so the mower is stored away. During my younger days I restored many motorcycles and wondered if I could modify this Colt to run with a modern carburettor such as this;

When I get the mower out I'll do a bit of measuring regarding the inlet port and stud centers; it will make another interesting project for me.

Kind regards, Colin.

Some of the practice welds in aluminium; I used lots of argon gas but now I can Tig weld gas usage is much reduced; lots of practice is needed.

 

[piglet11]

Colin
I quite agree about the cost of tools and materials.
I often buy good quality tools to do one job and if it's a repair, it always ends up costing a lot more than buying a new one.
But I suspect you are a bit like me. Buying new and chucking out the broken or repairable stuff runs against the grain.
Besides you end up with a thing of beauty, made in England.
How much better is that than buying some plastic rubbish at B&Q and it burns out after a couple of years, beyond reasonable repair.
You are going to need some strong fixings when you hang it on the sitting room wall.

 

[Retired]

Hi,

Thanks piglet; yes buy top end tools and buy once. I have power tools in the bench I might use once in a few years but when they are needed they are needed badly. Freud JS100 & Fein Multimaster top are two such tools and I have more just waiting for action. Places like Aldi sell similar power tools and these are fine for the hobbyist but for real work spend the money and buy a top quality tool.

Before I retired in 2000 we bought a White Knight tumble dryer that lasted until its warranty expired then it made an awful racket with a very loud bang each time it reversed direction it was truly a horrible machine. I then fully retired so this dryer was first on the bench; it was completely stripped; the rear bearing housing had broken free the thing being cheaply riveted a nasty piece of engineering; the motor fan was broken at its bore allowing it to virtually self destruct just to mention two major problems; the bearing housing was secured with stainless set screws and nuts; to sort the fan out I stripped the motor and reduced the spindle diameter on the lathe to accept a fan I had to hand; the only time it breaks down now is when the capacitor fails and as I bought a job lot of 200 capacitors years ago I think I've got it covered; this drier must have been a tea time special but 20 years on it now owes us nothing and is still in use most days; we bought a new filter for it about ten years ago.

England or Great Britain were world beaters and the mechanical revolution started here so why are we now so bad that we are buying cheap nasty imports from around the world whilst paying able bodied people to remain home on benefits; are we now so lazy it's a crime to get our hands dirty doing something commonly known as work? Made in Britain used to mean a great deal and whatever it was it was built up to a high standard not down to a low cost. Modern machines bristling with electronics will be dead long before our old cast iron machines without electronics. I don't trust anything at all with a circuit board installed but then I was taught on real machinery by real engineers not by fitters.

I'm sure I'd prefer our newly restored Colt mower hanging on our wall than an abstract Picasso? Brackets no problem at all.

Kind regards, Colin.