Welding Tips and Tricks

Hi,

Recently an engineer was asked to place a second valve hole in a set of heavy duty rims for an off road vehicle. but he made a mistake on one pair (how can he get 4 correct positions and 2 wrong ???? but that's for another day...)

Now the rims are complete overkill for the application: the swl of the rim is 6000kg EACH and the whole vehicle only weighs 4200kg so there's no issue with safety here but I now want to weld up the hole drilled by mistake. I also know I do not want to get any large area of the rim too hot; in other words I want the weld to be quick.

I plan to "plug" the hole with a round head mild steel bolt of the same size as the whole and simply weld the head to the inner surface of the rim and then cut the end of the protruding bolt flush with the outside and then weld it to the rim surface. However I know that rims flex and I wondered what rod to use to have a little flex in it?

First thought was chrome moly but then I wondered about maybe using a stainless bolt and 319 filler rod?

Would appreciate any suggestions people have on what people think is the best combination of bolt to plug the hole and best filler rod to use as the small amount of filler required in this situation.

thanks

MIG, TIG, Stick, Or Gas? I'd use a grade 8 bolt sawed off as long as your wheel is thick, and TIG with Hastelloy W. Be aware that some vehicle applications you are not allowed to weld on wheels at all. I don't know what your wheels are made of, (hence the Hastelloy W) I scrapped some truck wheels, discovering they are made of some incredibly tough steel.

Bill Beauregard wrote:MIG, TIG, Stick, Or Gas? I'd use a grade 8 bolt sawed off as long as your wheel is thick, and TIG with Hastelloy W. Be aware that some vehicle applications you are not allowed to weld on wheels at all. I don't know what your wheels are made of, (hence the Hastelloy W) I scrapped some truck wheels, discovering they are made of some incredibly tough steel.

wheels being a pressurized vessel comes to mind..........................................
am I worried for no reason?

Hi,
Thanks for the quick reply.

Definitely TIG. The wheels are steel and huge! The centres are 12mm plate steel and the rim band is 4mm folded plate. The centre is submerged arc welded to the rim band. The "mistake" hole is in the band and well away from the centre plate/band seam. I am going to preheat the area with a small propane torch (not oxy!) so there is a progressive heat flow into the area before welding.

I had a quick look at the Hastelloy W/242 rods and they seem to fit the bill in terms of joining dissimilar metals.

brokeitagain wrote:

Bill Beauregard wrote:MIG, TIG, Stick, Or Gas? I'd use a grade 8 bolt sawed off as long as your wheel is thick, and TIG with Hastelloy W. Be aware that some vehicle applications you are not allowed to weld on wheels at all. I don't know what your wheels are made of, (hence the Hastelloy W) I scrapped some truck wheels, discovering they are made of some incredibly tough steel.

wheels being a pressurized vessel comes to mind..........................................
am I worried for no reason?

That's why I am plug welding a bolt in there, keep in mind this where the [comparatively flimsy] valve is normally put through. But the valve has a rubber/silicon sealing surface so my main concern was to keep whatever filler material I am going to use ductile enough to cope with any flex in the rim band.

Kinda off subject, but if the wheel sees anything but low speed, it will be off balance like crazy.

Sent from my SM-G900R4 using Tapatalk

If you are not sure how to weld it, drill and tap for a small tapered pipe plug - use loctite and done deal.

79jasper wrote:Kinda off subject, but if the wheel sees anything but low speed, it will be off balance like crazy.

Sent from my SM-G900R4 using Tapatalk

This does see highway speeds of 130km/h but the rim and tyre weigh ~85kg (no that's not a typo 85kg!) and balance weights can be 200+g so the few grams of the bolt/weld shouldn't matter much .... I hope ... ....

MinnesotaDave wrote:If you are not sure how to weld it, drill and tap for a small tapered pipe plug - use loctite and done deal.

Don't you hate it when someone thinks laterally ..... Probably not enough bite at 4mm to use a tapered one but why not just a round headed bolt with proper high pressure sealant. It would worry me that the bolt could come undone but if it leaks then just clean the sealant out and TIG it in .....

Thanks for the thought tho, regardless of how I will do it I will thread the hole anyway!

Will you use tubes? Might there be a need to add a tube at some time. A bolt head will ruin a tube in a hurry.

icedvolvo wrote:

MinnesotaDave wrote:If you are not sure how to weld it, drill and tap for a small tapered pipe plug - use loctite and done deal.

Don't you hate it when someone thinks laterally ..... Probably not enough bite at 4mm to use a tapered one but why not just a round headed bolt with proper high pressure sealant. It would worry me that the bolt could come undone but if it leaks then just clean the sealant out and TIG it in .....

Thanks for the thought tho, regardless of how I will do it I will thread the hole anyway!

Too thin for a plug, how about a steel rivet with sealant or epoxy to be sure?

What is the actual diameter of the problematic hole?

Instead of a bolt, could you just copper-back the hole and MIG/TIG it in stages until it is filled, then remove the copper backing, and then grind back to the original material form?

I may be over simplifying this, but why not just put a valve stem in that hole also.

I hate to be too "back-yard mechanic" in a welding forum, but you could just put a second valve stem in the misplaced holes. That would use a proven method to adequately seal the hole (you already have one in each wheel). It would also eliminate all the agonizing about possible welding heat damage to the base material of the rim.

Lee

@Lee,
Great minds think alike, but some type faster.

Len

Braehill wrote:@Lee,
Great minds think alike, but some type faster.

Len

-Jonathan

Forgot to mention: ER80S-D2 Low Alloy Steel filler might be suitable.

Braehill wrote:I may be over simplifying this, but why not just put a valve stem in that hole also.

When I first read this that was the first thing to pop in my mind. Just put a second stem in there and call it done.

MinnesotaDave wrote:

icedvolvo wrote:

MinnesotaDave wrote:If you are not sure how to weld it, drill and tap for a small tapered pipe plug - use loctite and done deal.

Don't you hate it when someone thinks laterally ..... Probably not enough bite at 4mm to use a tapered one but why not just a round headed bolt with proper high pressure sealant. It would worry me that the bolt could come undone but if it leaks then just clean the sealant out and TIG it in .....

Thanks for the thought tho, regardless of how I will do it I will thread the hole anyway!

Too thin for a plug, how about a steel rivet with sealant or epoxy to be sure?

Yeah this is what we did in the end. We contacted the manufacturer of the wheel and found out that the rims are 250 series steel which basically means there is no exotic alloys involved and welding is fine. So we simply welded a stainless rivet in with 309 filler and ground it as flat as we could.

Braehill wrote:I may be over simplifying this, but why not just put a valve stem in that hole also.

Unfortunately not! The hole was on the outer surface of the rim and pointed outwards. As this is a 4WD truck the stems need to be inside and pointed inwards otherwise they would get ripped out the next time we went through any mud or loose rocks or even sand.

TRACKRANGER wrote:Forgot to mention: ER80S-D2 Low Alloy Steel filler might be suitable.

Thanks for this thought. I decided to use a 309 cos I was a little worried about the filler corroding and it has enough Ni to still give a little flex.

Just wwanted to say thanks to everyone who replied; your suggestions were really appreciated and I hope they help others with similar problems.

thanks

Glad you've solved it!

Best thing I saw was consulting the Mfgr, to check the alloy, and going ahead with the fill and weld.

I've no doubt this will come up again in one form or another.

Steve S