Weld SS sheet to Dump truck bed

[thecrow1]

So rock salt is destroying my 1 ton bed on my 3500. I want to weld a stainless steel sheet food grade don’t need it thick just to cover it basically to the bed floor with a 6 inch sides. My setup is a
stick welder; would this work and if so any recommendations on settings on the welder, type of rods, techniques etc would be greatly appreciated thanks in advance ps just can’t afford to have a professional do it I’m on my own here

 

[nadogail]

Been a while (25 years) since I have welded stainless. I think I used 309 Stainless rod, Electrode Negative, and it was pretty small diameter. I think my boss the ordered electrode from McMaster Carr.

 

[dogdog]

309 stainless rod if you are welding mixed stainless steel to steel. Or unknown stainless

Otherwise 308 for 304 stainless which is common label food grade.

If it is restaurant stuff I think they also called 410 or something series food grade but those are magnetic then used 309

I know they sell stick welding electrodes for both not sure how to on thin sheets

 

[thecrow1]

309 stainless rod if you are welding mixed stainless steel to steel. Or unknown stainless

Otherwise 308 for 304 stainless which is common label food grade.

If it is restaurant stuff I think they also called 410 or something series food grade but those are magnetic then used 309

I know they sell stick welding electrodes for both not sure how to on thin sheets

Any preference on settings on welder

 

[dogdog]

Any preference on settings on welder

I won’t know your welder let alone stick welding. I believe the setting would dependent on welder and the electrode.

 

[Wrench97]

Get the steel clean no rust, use 309 1/8" rod if you have a AC machine the polarity won't make a difference.
Keep the amps 90 or less, it's going to crack no matter what over time.

 

[joe49]

Your welding to steel so 7018 will work fine. Size of rod and amps depends on material thickness. Thinned out floor and/or thin SS smaller rod and lower amps. Sheeting a floor needs to have cut outs (small holes or slots) for welding in the field of the plate. My thought is to use 1/4'' AR400 plate. Less trouble down the road, if you ever need to repair it again.

 

[boom_bap]

Any reason to not use fasteners and just bolt it to the target area?

If you want to weld stainless to the steel bed then use either 309L or 312L.

 

[Garage Junkie]

Remember that the void you might leave underneath will hold moisture and can accelerate the corrosion of the original bed beyond what it is already doing. When all is said and done, you might be better off to source another bed and keep it until the one you have is too far gone, then swap them.

 

[fordkid88]

The stainless will slowly rust on the bottom side from being contact with steel.

 

[thecrow1]

Remember that the void you might leave underneath will hold moisture and can accelerate the corrosion of the original bed beyond what it is already doing. When all is said and done, you might be better off to source another bed and keep it until the one you have is too far gone, then swap them.

Might just buy an aluminum bed next

 

[jrsavoie]

What gauge of stainless?

You may want to invest in a wire machine.

Definitely DC reverse if using stick. Or you could tig straight polarity with the same machine.

I've had good luck welding stainless to steel with 3/32 or smaller stainless rod or 7018, 8018, 9018 or 11018 low hydrogen rods.
Keeping the rods warm and dry doesn't hurt a thing.

I would rust convert and use a weldable primer before installing the stainless

 

[thecrow1]

Not sure but it will be high end he referred it to as a food grade? I’m concerned about the gap between the SS and steel moisture salt etc and also can’t use bolts, I have a stick 240 volt so I’ll probably attempt it with one of those rods

 

[jrsavoie]

Ask the gauge.

As long as you keep your heat on the base metal you should be fine.

If your welder isn't DC, I'd get a DC welder. I've seen some nice ones for Sale on Marketplace, for in the $200 range. I thought they were bargains.
A Miller Thunderbolt AC/DC or about any AC/DC Miller, Airco, Hobart or Lincoln with fine adjustment is good.
The big clickers are garbage.
Unless it happens to have a setting that you can use all the time

 

[Jim greengo]

Is it a flat bed or pickup bed?
How about just welding some steel tread plate down in there? Would probably take more abuse than the stainless will,and cost a hell of a lot less to maintain.

 

[boom_bap]

I'd just fluid film the car personally. I agree that you're going to get trapped moisture and it will rust between the layers.

 

[Wrench97]

Welding a new floor in a steel dump body is a pretty normal service procedure on older bodies, even without the salt running stone/sand/coal out of them wears the floor out over time.
Personally I'd just weld 1/8" steel plate over the old floor, by the time that wears out the rest of bed will shot.

 

[dr_clyde]

Save your money, this won't work as well as you think it will.

Unless the entire box is made from stainless, you'll have more issues with corrosion from the gaps and sandwiched parts than from just leaving it alone. Part of designing a good "corrosion free" design is allowing for drying and drainage.

The stainless itself will probably be fine, but the rest of the truck will just rust out around it.

 

[welder4956]

300 series stainless does not play well in salt. Chloride stress corrosion cracking along the sides of the weld and pitting corrosion is likely, although you may get a couple of seasons out of it before cracks too bad.

 

[Firebrick43]

The stainless will slowly rust on the bottom side from being contact with steel.

And actually accelerate the rate of rusting out of the bed. Corrosion needs water, oxygen, and an electrolyte(salt is a really good one). Since the steel underneath is less noble, it will act as the sacrificial anode when the stainless has corrosion attacking it as well.

By welding a sheet over the bed, it will rarely dry out between the sheet and the bed floor as Dr clyde noted. You will never keep the salt out either.

 

[gearhead1]

I think 309L Wire is the correct one and there is a difference between 309 and 309L, which is carbon content. I know this is a dump truck not an ASME pressure vessel. Where I work, we make ASME pressure vessels and we have to use 309L wire when welding a 304 stainless steel tube sheet to a carbon steel tube. From what I’ve researched, if I remember correctly, the 2 different metals cool at different rates and are prone to cracking. The 309/309L wire compensates for this, but I don’t remember which elements allow it.

Alloy ER 309 / ER 309L Stainless Steel ER 309/ ER 309L

How To Weld Stainless Steel To Mild Steel- Complete Guide

It is possible to weld Stainless Steel to Mild Steel or Carbon Steel using E7018 or ER70S-2/ ER70S-6 Welding rods although it is not suggested to do so. The reasons are:

www.materialwelding.com

 

[gearhead1]

This explains technically the why…….go to page 35.

https://nickelinstitute.org/media/1854/weldingofstainlessssteelandotherjoiningmethods_9002_.pdf

304 stainless is austenitic.

 

[gearhead1]

We use mostly 304 SS at work, but for special applications requiring higher corrosion resistance, we use 316. You may want to use 316 if you can.

 

[Walkers]

Isn’t this very situation what the spray on bed liners were developed for (body corrosion on mining vehicles)?

 

[Garage Junkie]

At the mines where the road salt is made, we used minimum 316 stainless for anything that needed to last both from corrosion and abrasion. Otherwise, we used carbon steel with epoxy paint jobs and tended to use much thicker steel than necessary to allow for loss of section from corrosion. Once the original paints or coatings failed, we would try to blast and re-paint, but it was a losing game from there on. Most structures on the surface facilities would last no more than 20 years. Vehicles, including Cat 988 loaders, would last 6-10 years before they were scrapped or traded in.

 

[michaelf]

What gauge of stainless?

You may want to invest in a wire machine.

Definitely DC reverse if using stick. Or you could tig straight polarity with the same machine.

I've had good luck welding stainless to steel with 3/32 or smaller stainless rod or 7018, 8018, 9018 or 11018 low hydrogen rods.
Keeping the rods warm and dry doesn't hurt a thing.

I would rust convert and use a weldable primer before installing the stainless

7018 lots cheaper than ss rod and works well for that job

 

[jrsavoie]

7018 lots cheaper than ss rod and works well for that job

Depends. I bought a lot of stainless rod once for a very reasonable price

 

[RPH]

Any reason not to consider the proper tool? After all, it is Garage Journal here.