so im building this TI exhaust for the lambo and im practicing buffing it on some spare tubing i have. i cant get it smooth to where i can take the buffing wheel to it with compound.
it seems to be very pitted so if i try to use the buff wheel/compound just as is, turns out looking like *** because all the compound gets stuffed in the tiny pits and looks black.
so i've tried 3m roloc/buffing pads from course to fine, dry and wet, tried sandpaper from 220 grit down to 600 grit. also tried a different 3m wheel thats really soft but i still cant get the pitting out. any suggestions?







i'd hate to just leave it with a brushed look

 

What grade titanium are you using? If its not CP2 grade then its very very hard to get the "pitting" out. If its a AL series, it smears do to the aluminum content. Shoot Danny at fabworxs a pm, he is very informational on this subject. Cp2 should shine right up with green roloc discs like pictured. Hope this helps.

 

this is the best i've gotten it to look so far, theres some shine in it, but still not a smooth surface

 

using 3" CP2 seamless from titaniumjoe.
danny said pretty much the same thing you did, green roloc pads. but i must be doing something wrong because i cant get it smooth.
do you use slow/medium/fast speed?

 

The CP2 polishes fine. Use the scotchbrite like you mean it.
I used a flap disc (80 grit) to get the surface smooth on some
Rough sheet. Then red scotch discs, then 1000 grit wet sand, then 2000
Grit wet. Then, buff with polish. Lots of work for Ti.

 

Your going to have to go more course IMO first then work your way down.

Does it need to be more shiny than that, looks fine to me, and the extra 0.2mm or whatever will be your friend when it comes to heat material strength.

 

this is a lambourghini im building. i want it to be PERFECT.

 

I like that brushed look, the polished look won't look good for long. One finger print and its game over. Try hitting it with a brown coarse pad or a 80-100 grit d/a sander to remove pitting. Then go to green 3m pad, then to Christmas tree green compound.

 

hmm, i was initially afraid of using anything that coarse on it but i'll give it a try.

 

ok so i used a 120 grit flap wheel on my angle grinder, then brown roloc pad then green roloc pad then buffing wheel on my bench grinder using green compound.
the good news is, no more 'natural' pitting, but it seems the green roloc pad is still too coarse as it leaves scratches in the metal that the buffing wheel cant take out, i might need a more powerful bench grinder/buffer.

 

3M 7480 Roloc for surface imperfections such as what you described, after that use the green one, and finish it off on the buffer wheel (polishing wheel).

Also, give some 3M Trizacts a try. I use the 80 grit ones all the time for taking out scratches on CP 2 and 6AL4V

 

By the location of where the parts are it doesn't look like they will last very long if the car is used how its intended.

 

what wont last long?

 

I think it'll be fine, once it reaches a certain temperature you'll start seeing some alpha casing which isn't necessarily a bad thing, it just means that the structure of Ti has been hardened and can become very brittle if temperature goes beyond that point, I think 1650F or something, somebody correct me I'm wrong I'm no material science major but I've worked with Ti for 7 years I think I'm on the right page.

The company I used to work for built a prototype header out of Ti for one of John Force's cars, he ran it down the track once and ran over the header. I don't know the full story but I think the header was close to it's melting point, began to sag and fell off. The company even told him it wasn't a good idea but he still wanted it.

found something about it.

A few years back Johm Force's team was testing titanium headers. Some NASA geeks had told Austin Coil (Force's crew cheif) that they would work better while being lighter. Austin said they would not hold up to the heat and raw fuel. Nasa guys said they would.

So the headers were built. They were put on Tony P's car and during the first test run proceeded to burn apart where the header makes the up swing. Now with nothing more than 8 pipes directing all the exhaust flow downward Tony was in deep. John Force told the story as how Tony's car was comming to the traps "hovering" in the air for a split second, all 4 wheels of the ground from all of the exhaust pressure.

Autsin ofcourse said "I told you so" to the NASA boys and that was the end of the Titanium headers.

Just a little known fact I thought you might enjoy.

sourced from ViperClubOfAmerica

 

I use a baldor 1.5hp 3400rpm buffer. You couldnt bog this motor down if you tried. It has been known to catch the cotton buffing wheels on fire Haha

But it would buff those marks out very quick with green compound. I'll polished some 3al tomorrow and post up how i do it

 

me love you long time!

 

this is the best i've gotten so far

 

i ****ing win!

here's what got me these results:
6" orbital sander with a soft backing pad and 240 grit paper@about 3000rpm to grind down the pitting
then 400 grit sand paper wetsand by hand, then 600 then 800/1000 wetsand by hand and finally buffing wheel with green compound.

what a BITCH!

 

good job on finally figuring it out!

 

i need a more powerful buffer...
colin, did you buy yours locally?

 

when i ever had to polish stainless ( i only assume this would work the same on TI ) I think the procedure was something like 180, 240, 400, 800, 1000 or 2000 all on a da sander then it would go to the buffer and get the course pad (real stiff pad) and get a white bar. Then onto the soft pad and a different bar ( can't remember atm) this would produce a damn nice polish on the tubes. It really depended on how patient you were with the da. also the starting grit depends on the surface.

 

We went through about 4 jet buffers (each replaced one after the other under warranty) until we got fed up and bought a couple of the baldor 412b 1.5hp 3ph units. 2 years so far and no issues. They are like $800. Don't think about it, just do it.

http://baldor.com/products/detail.as...s|vw_GrindBuff

 

i woulda pulled the trigger on that in a heartbeat if my building was wired for 3phase. i dont ****ing get it why a brand new industrial complex wouldnt wire them for 3ph. FML

 

I have the same one crmb is talking about. 412b I believe it is.
1 1/2hp single phase, 3400rpm. Got mine brand new for like 689-800$ used they go for close to the same price. It's amazing how strong baldor electric motors are. Never heard of one braking. It's a industrial grade buffer, so you get what you pay for. There so silent while running and well balanced I left mine on half the day and didn't even realize it till i went to use it Haha

 

thought id post this in here, the reason i swear by these buffers is for this reason. i was doing some side work for boostlogics on my spare time. they have a old 412b baldor and i had my buddy (McRussellpants) buffing some welds els for a manifold, and well, lets say he went over board HAHA!!!

by the way, this is why i bought one. you couldnt slow this motor down if you parked a car on it...

Keep in mind this is a (or was) a cotton buffing wheel lol



and here is a ton of work put in. just because the buffer is good, doesnt meen polishing is done easy by any means

finished product