I might want shock absorber mounting struts welded onto the chassis of my caravan. I assume it'd be cheap enough to get a garage/welder to do it, but I'm a little concerned that welding so close to the boards would set fire to the caravan..

How close can things be to a weld before they catch fire?

I read that as "Wedding question"!!
And then there's talk of mounting struts!!! 😯

8)

Very 😯

Whats the distance between the weld spot and the boards? are they touching? If so, youre talking seconds , if not then even a few centimetres air gap means you can put a heat sheild between them.

The heat of the weld will travel quickly too along the metal, and will be very hot for the first 10cm of metal away from yhe weld

As long as the wood close to where you are welding isn't too thin I'd doubt its too big a problem – the wood might get scorched but it shouldn't erupt into a flaming death ball unless its very thin, plastics or plastic coatings on the wood would be more or a concern. I'd expect the floor to be reasonably thick, but the walls and any insulation would be more vulnerable. There are various heat proof pads that can be used to protect anything vulnerable, but the welder should know better than to weld if harm is likely to be done.

If you really can't weld directly without doing harm could the struts can be welded onto a plate then bolted to the chassis?

Is the wood actually touching the metal to be welded ?
I use scrap bits of aluminium sheet wedged between the weld and any nearby plastic air pipes or other flammable stuff when possible.
Even if it's touching, wood takes a fair while to catch fire.
It should be possible to do a quick run of weld, then douse the area with water with only minor scorching of the surface.

Any chance of a photo ?

Good grief! You have a Prius AND a caravan? TopGear heresy! 😆

Ignoring the heat problem which would be hard to know without seeing, just be a bit wary about how the shocks affect the dynamics of the towed trailer.

I'm thinking skidartist's idea might be best. The biggest problem bit is the mount on the other end of the shock, which needs mounting on the suspension arm – a pretty thick heavy bit of hollow steel. I could pretty easily bolt a long bit of something to the chassis that would spread the load and but up against the top of the members.

CK – re dampers: Caravans are built on stock chassis from trailer companies. In Europe, vans come with dampers (in Germany it's a legal requirement to have them if you want to drive at 100km/h) but for some reason they didn't fit them here until recently. Some companies have the mountings already there for them like Alko, but mine is Knott. Knott do make dampers and fixings, but the fixings are for welding on. It's meant to seriously improve the towing of the van.

Any welders/mechanics in the South Wales/West area fancy a small job? 🙂

OK, that's cool, just checking you've thought it through and are using safe parts, that's all. It wasn't the presence of them that was concerning me, more the change and the possible use of unsuitable ones.

🙂 I've got the Alko ones rated for the correct weight, but they could easily be made to fit I reckon.

Almost bought a welder from Halfords yesterday too – I saw sense tho and managed to control myself!

Remember years ago my boss welding some metal that had wood bolted to it – had me waiting on the other side with a bucket of water to fend off any conflagration. And he knew what he was doing.

Get someone with a TIG set, minimal heat and very directional.

If its galv, i wouldnt touch it for a gold clock.
Google zinc fever.

Pint of milk before you start and you'll be fine, fact!

You'll be reeet. Its not like welding a petrol tank 😉