Making Blast Pipes

July 28, 2021

Making Blast Pipes

I decided to take another crack at making blast pipes since I wasn’t too happy with my first attempt for various reasons and had learnt some things after making the first one.

I originally freehand cut the merge on the vertical bandsaw then realised I could just tack a straight to it then clamp and cut it normally ensuring a much straighter cut and less damage to the blade from me twisting.

With the merge cut I did the straights and then sanded everything to 2000 grit because I had too much free time. I also remembered the stagger correctly for s chassis since it’s going on Josh’s s15. I did it the opposite way on the first set and ended up cutting them even.

The merge I only polished to 1000 since I couldn’t be bothered but the straight was to 2000. Used Bowdens metal polish on my DA.

Cut a 15 degree slash on the end too. I think it looks nice especially when the blast pipes kick up.

One thing I learnt from making the first set was to weld the straights first! I welded the merge first originally and had a terrible time trying to weld the straights in the gap between the two pipes. Pretty much had to weld blind the first time when it came to that section.

Also remembered to count my pulses/dabs for better visual consistency.

Tacked the merge and then clamped the tips together to get the gap I wanted before tacking the brace to hold it in position. I just used some 10mm stainless round bar.

Then it was time to weld the merge. Some tape to help avoid scratching from flipping it over.

And done. The tight crack is always a pain but I only found out after you can weld that bit from the inside instead.

Next is to cut the merge to weld the straight section. Roughly marked out with an offcut where to cut.

Back in the band saw

Little bit of sugaring. Ideally needed a die grinder or even better backpurge to avoid it in the first place.

Next problem to solve was fitting round tube to a not so round area. I first started with crushing the end in a vice and hammering.

After another hour of crushing and hammering I got the fit up a lot tighter.

Which makes it much nicer to weld

I then cut it to an inch but probably would’ve been better to do 2” since the tube was slightly warped still at 1” from the hammering and crushing. I kept the piece I cut off to use to build the rest of the pipe so it will still match up.