Steel for welding

[FrenchStag]

Good morning and best wishes for 2025.

Sorry Im sure this has been answered before on the forum but for steel to weld things like a small hole in a battery tray and then something a bit chunkier like a chassis rail, I seem to have a choice of 1 or 1.5mm at the local DIY place. Is this about right.

And is galvanised steel a good choice or is that daft.

Finally Im intending to use Hammerite on the underside of the car once I have wire brushed the surface rust off and dealt with any holes. Is this sensible.

Thank you very much

Simon

[mjheathcote]

Welding thin steel is tricky so I would go for 1.5mm.
You do not want to weld galvanised steel for it gives off toxic fumes.

[richardthestag]

Ideally match the steel like for like, adjust the welder to accommodate. If it is blowing through and you are chasing holes then you either need to make a bigger repair because the original steel is rusted too thin or turn down the wire speed / power setting depending on what welder you are using. I usually get the power setting right for the thickness of steel and then adjust the wire speed to suit.

Avoid galv, or anything with a cold galv spray. when you weld it gives off white plumes of smoke, breath these willow the wisps in and you will feel very sick.

21c Hammerite is a very poor relation to what we used to use back in the 1980s. I would probably use a 2k chassis or underbody paint as supplied by the likes of Rust Buster Rust.co.uk

[FrenchStag]

Thank you. Having great fun with the new PI. Not sure when it will run again but its quite a beast and (mainly) very sound. Stripped down the rear drum brakes today, thankfully its cut and paste of the Stag. Very happy with new toy.

[ramjam2005]

+1 for what everyone else has said .. and yes ..welding galvanized is a BIG no no .. and there are better products to consider than Hammerite - Rust converters, Rust encapsulators, POR15 Chassis Black etc.

IF you do end up chasing holes on that battery box, the 3 panels are available separately to rebuild it, but means more surgery than you may intend.

[FrenchStag]

Thank you, appreciate the lung-saving! the hole is small and mainly cosmetic its just something that will bug me if i don’t do it.

Also thinking of putting some kind of rubber matt under the battery as seems a bit unyielding to tighten it directly onto the metal tray, is this worthwhile doing?

[jbuckl]

I had a battery that was a bit too shallow, used two strips of mahogany to lift it up.

current battery is correct height.

using rubber can trap moisture though.