I want to know if anyone has experience at welding on gas shock absorber. I need to cut and weld a new part ( located in the red circle, on the picture ). Is there any danger ? If I put the ground clamp close to where i will weld..
Some motorcycle shocks have rebound adjuster stacks in that section of the tubing, you would want to make certain that is a solid piston rod and not an internally damped one that has some role in the workings of the shock. If you have an old one I would cut off the section you are planning to weld on and see. If solid then doable assuming you control the heat input as to not stress the internals and seals on the shock.
Also be aware that the shaft is most likely highly polished chrome finished. If you get the slightest surface damage from the earth clamp that could very quickly tear the seals up resulting in loss of gas pressure and ultimately shock fluid.
GarryH wrote:Also be aware that the shaft is most likely highly polished chrome finished. If you get the slightest surface damage from the earth clamp that could very quickly tear the seals up resulting in loss of gas pressure and ultimately shock fluid.
Probably a good example of a time to use the braided copper strap for a ground contact. I remember seeing that in one of Jody's videos, and wondering when/why to use it...
As the others said though, watch out for heat input. I boiled the grease out of a ball joint once, through heat conduction from another area. With the gas charge inside the shock absorber, there is the potential to have a geyser if the seal overheats and looses it's structural integrity.
Thanks guys for the inputs.. Actually it's a generic photo i took from Google.. I'll perform this modification
on a rear car shock that looks almost the same. I will machine a small tube to get the rod 2" longer, to allow
the shock to operate in the optimal condition while the bracket on the car has been moved.
My concern was more about explosion due to the high pressure gas inside the shock body.. Like that HF can
spark inside or some other similar things like that.. I'll be like 10-12 inch far from the gas tube, but there's
no second chance when it come to explosion..
RR,
Let the shock fully extend, then wrap a wet rag around the shaft close to the cylinder housing to stop the heat transfer through the shaft. If you don't spend any more time than you have to welding this you should be fine. The High Freq. isn't likely to cause an explosion with hydraulic oil.
+1 what Len said and the gas inside it is nitrogen. It doesn't leek as fast as plain old air and is very stable volume wise with temperature swings. For the same reasons this gas is good for using in your car tires. It isn't flammable.
