How many welder / fabricators know this metal finishing technique? ASMR.

[@3073Sean]

Damn bro, you know how to polish some pipe!

[@FuelExhaustsLtd]

Thanks very much. I’ve been doing this for about 30 years and polishing is a very labour intensive process. Many people do not realise that there is a lot of skill involved in metal finishing, not to mention it’s a very dirty process and is hard graft but as you can see the end result is worth it.

[@marcosdecezare3412]

If you use all this process in your fabrication , your exhaust is the better of the world

[@FuelExhaustsLtd]

We used to use this process when we mirror polished our parts but modern motorcycles eg. adventure bikes no longer have polished parts. 3 or 4 years ago we invested in machinery to produce parts that are media blasted and have a satin finish to match the look of OEM kit. We also ceramic coat parts now as this is popular too.

[@brucejenner4800]

We all know that the gradual reduction of grit size makes for a better surface finish. But is the slight reduction of the pipe diameter to achieve the finish detrimental to any engineering parameters?

[@malachy1847]

He's polishing the Pipe moving very small amount of the parent metal, PLUS he 'Purge' welded the pipe allowing for not alone good penetration, but creating a inert chamber where the molten metal could cool without oxidation because of the inert gas envelope thus leaving a large of mount of strong fused in a nice bead of welded metal spilled out on the root gap becoming maybe even sometimes even stronger that the original pipe itself...obviously if it was in Industry, the Pipe schedule would be chosen by Calculations to withstand multiples of the working Pressure of the media being transiting through same...but in this case it's just for a Car and we can see it is just Light Wall...Exhaust Pipe...

[@FuelExhaustsLtd]

No Bruce let's put it this way, in my 30 years of welding I have never had a purge welded joint fail. I would say it is not dentrimental as only a very very small amount of material is removed. Malachy1847's comment below is absolutely spot on. In my experience, the weakest part of the welded joint is actually the heat affected zone (HAZ). This is usually the area where the welding (heat and cooling besides the welded area) causes the failure. I hope this answers your questions. Thanks for your comments.

[@FuelExhaustsLtd]

@@malachy1847 thanks for an absolutely spot on detailed explanation. I could not have put that better myself! Hope you enjoyed the video!

[@yt66228]

Nice job. This is done without back purge?

[@FuelExhaustsLtd]

No this is back purged. See the video around 1 minute 28 seconds where I put a bung in one end and argon gas supply into the other. You will see the silver grey tube sticking out of one end.

[@brucejenner4800]

I'd say it was done with out purging. The joint interface must have been a perfect butt joint, then blended together with tig. But I don't think there would have been full penetration of the weld or the weld zone would have obviously sunk below the mean diameter of the pipe. To me, this cannot be a mechanically sound joint?

[@FuelExhaustsLtd]

@@brucejenner4800 check out the video at 04:58-05:03 where I show an internal view of the welded joint. It is very difficult to show the inside of a tube on camera but if there was no purging, there would be an oxidized black area instead of a shiny weld.