Quote:
Originally Posted by Graham
You should definitely do what you consider the "right way" for you!
I have been around the block a few times, and the places I found that repairs rusted down the road were often adjacent to the welds. Not easy to rustproof backside of welds in some areas, like rockers. The part highlighted above can work both ways 
I see no problem using mechanical joints, especially for non-critical jobs like closing up a hole in a firewall. I suspect the S/S rivets I have used are plenty strong enough. Riveted joints are standard in many applications - aircraft, ships, boats etc.
Interestingly, the MB factory/dealer kit for replacing troublesome previously welded spring perches on the W210, uses heavy duty pop rivets that I believe are Monel. And this IS an important structural joint. Previously, the sheet metal welds rusted out under the seam sealer where they couldn't be easily inspected.
Just my 2c worth, but carry on, you are doing a great job. |
I don't mean to belabor the point, but there are serious differences between aerospace use of rivets and those you've used for bodywork. The rivets you're thinking of are part of a skin, not a frame of an aircraft. Secondly, the rivets are of the correct material. If you've used stainless steel rivets in a low carbon steel environment, you'll get galvanic corrosion, especially when exposed to water of any amount (I know this well from my day job).
Sure, the w120 spring perch does use rivets. 6.4 mm diameter high strength steel rivets. I'm guessing on the sheet metal thickness, but even at 3mm thick the diameter of the rivets is double the thickness. These are really beefy rivets of a specific material.
This is a different application as well as this spring perch joint doesn't flex, the floor of the car does. Cyclic loading of a fastened joint reduces the ability of the fastener to maintain a clamping force when the joint has movement. Cylinder head bolts are torqued to yield; that joint isn't going to have any movement. With rivets in the floor, the joint will have flex as the material around it is quite flexible and never was designed to be rigid. That means that over time the rivets will be cycled and loosen their clamp on the panels. This will lead to the rivets rounding out the holes and eventually failing.
The final important thing is that rivets are not a waterproof joint. They may mechanically join a seam, but even the overlapping material is not waterproof. Unless a rubberized sealer tape/material or hardening compound were added between the two sides of the material, this is not waterproof. (And if sealer were added between the panels, then rivets would be even worse of a choice). Seam sealer should always be considered a secondary waterproofing measure as it will break down over time.
All this is to say that rivets can and should be used in applications where they have been specifically designed to be used. Floor panel replacement is not an area where rivets are a good application.