Refurbishment and Repacking of Ducati Performance (Remus) Cans

[billywiztheelder]

My cans were starting to show a brown tinge on the carbon fibre casing. Until that time I had not realised that they need regular repacking. The cans you will see below have only done 7,500 miles. For the Hooligans amongst us see the Addendum!
Acknowledgements and thanks for inspiration and guidance to:-
Weeveetwin for the initial guidance and suggestions on refurbishing the carbon fibre sleeves.
Gillan900 for research on replacement stainless steel straps and further encouragement.
chas for sourcing the laser cut the stainless steel straps and posting them before I even had a chance to remunerate him.

Dismantling

This is the first one, rather sad with a mild case of road rash so there will be some metal refurb as well as the carbon fibre.
Tools used were:-
Drill, hammer, thin parallel punches, nail punch, rubber mallet, 6mm Allen key, pop rivet gun, Dremel for polishing out the road rash in the stainless steel can end.



The pop rivets are stainless steel so a special mention for the drill bits I used, they are cobalt and I bought them a while back to drill a hole in the brand new Franke sink top as the kitchen fitter refused to do it. These ones have twin points to prevent skating but that is not essential for the task in hand. However they must be used at relatively slow speeds, you can see the recommendations on the packets.

Before you start to drill off the rivet heads have a look in the hole of each to make sure that the head of the mandrel (the bit that breaks off and stays in the rivet) is not close to the rivet head. If it is the drill point will sit on it and spin and you won’t get very far. A thin punch will push it down into the body of the rivet. In this photo you can just see where the drill bit tip has been sitting on the mandrel head. I left the hanger on the can as it proved useful to steady it and found that there was only one rivet at each end that I could not get to with the drill when held like this. Once the heads have been drilled off you can punch the rivets into the can. Gently, gently does it. There is definitely a knack to it. The rivets are 4mm so the closer you can get to that the better. I ended up using my long tapered nail punch.



If you are not intending to refurbish the carbon sleeves then I would suggest laying the can on some soft padding to stop any scratching from the stainless steel chips that are going to be lying around from the drilling process.



After the first few taps you will know whether or not the rivet is going to be difficult. You may find after drilling the head off that one side of the remaining barrel of the rivet stands more proud than the other. Try tapping on this rather than the low side. The first can I had 4 or 5 difficult ones. The second there was only one. Whether this demonstrates that my technique was improving or not, I don’t know.



If you are refurbishing the carbon fibre sleeve don’t forget the rivet holding the hanger fixing plate in place. Its removal facilitates the sanding down of the carbon fibre as you do not then need to work around it. This can be drilled without removing the hanger first.



With all rivets punched below the level of the carbon sleeve we can begin to take it apart.
This is where the rubber mallet comes in useful. Use it to gently rap the tail pipe from alternate sides and you will see it start to come out.



As you can see from the photo the flange is about 15mm wide.
So be ready to wriggle it out the last bit by hand rather than have it fall on the floor.



I tried the same technique with removing the carbon sleeve from the front end. Whilst you could see it just move it was not going to come off. So grasping the wadding I gave an experimental tug and found that it moved. Pulling a bit harder and it was definitely coming out.
So here is the tail end of and it had me wondering if I really needed to do all this, looks OK to me.

A few more tugs and out it comes and the answer is a resounding YES.
Just look at it. Where did it all go to because whilst the inner tube has gert big perforations in it, this is then wrapped in a number of layers of an extremely fine stainless steel mesh which is spot welded onto the central tube.



If you have drilled out the pop rivet holding the hanger fixing plate this will come out with the wadding, so don’t lose it.
The wadding in the first can came out in a jiffy whereas the second one was a pig. It was stuck to the inner lining of the carbon sleeve at the very tail end. Having separated the wadding from the sleeve it did eventually come out. Loads of tugging and be careful not to start pulling it to pieces as you will not have anything to pull on. I found trapping the wadding between all fingers and palm of both hands with the can clamped between the knees was the way to go. Pulling on alternate sides also seemed to help.



Once the wadding is out hold the can by the front pipe vertically and then use the rubber mallet to gently rap the sides of the sleeve towards the tail end on alternate sides. Once again, take care and grasp the sleeve in the other hand for the last few mil to stop it crashing to the floor.




So here they are apart and you can see that I have mutilated the wadding on the second can somewhat in pulling it out. It looks as though it was entangle with the stainless mesh as well because small portions of it came away.

Refurbishment of the Carbon Fibre sleeve

An experimental attack of the stickers showed them to be well and truly baked on and brittle. They had to be gently scraped off and the remaining residue cleaned of with brake cleaner to prevent subsequent clogging of the abrasive to be used. I not only had to prep the surface to receive the lacquer but also remove the evidence of contact with the blacktop. On the previous advice from weeveetwin I needed to finish off with a 600 grit paper so the pack I bought had 240, 400 and 600 grades for £2 ish from B&Q. I mentioned at the beginning that I had noticed a brown tinge to the otherwise black of the sleeve. When this was experimentally attacked with the abrasive dry the resultant dust was initially brown turning to black which suggested that the discolouration was a surface condition only and not through the entire can wall. Once this was seen I reverted to using the abrasive wet to avoid any dust inhalation. The sleeves were sprayed with Halford’s Petrol Resistant Lacquer. As weeveetwin originally pointed out it is essential that the manufacturer’s recommendations on time between and number of coats be closely followed.



I could not source exact replicas of the DP stickers and the most acceptable found can be seen in the photo. They are extremely thin foil approx 145 x 35 mm so I knew that it was going to be one shot at applying them. I had already established that they needed to start 50 mm from the end of the sleeve, but how to ensure they were aligned with the axis of the can had me thinking. In the end I threaded a cord between the rivet holes in each end of the can to give a pair of tram lines. The human eye then has good reference points to give acceptable horizontal and vertical positioning.

Repacking

As shown in the photo, the Workmate proved extremely versatile in restraining the can facilitating the repacking/wrapping process.



Here is another way in which I supported the can without its end cap. By clamping a dowel or cane into the vee joint of the work surface which projected out to one side I then slid the central tube of the can onto it.



With the sleeve loose fitted to the inlet I took a rough measure of the length needed for the wrapping of the wadding as the central exhaust tube does not reach the end of the sleeve by about 15 mm. There is a spigot in the end cap which fits over the end of the central tube.




Now the wrapping can commence. I found that the final spot welds holding the fine stainless steel mesh to the central tube had failed for the outer layer so this was taped down before the mineral wool was wrapped around it. If the sleeves were circular it would be a lot easier but they are oval so as the wadding is wrapped around the top and bottom, extra wadding needs to be entrapped to give the desired profile.



This is the packing I used for the wadding. It is mineral fibre acoustic insulation quilt that is installed in drywall partitions and foil faced on one side. We shall see in the goodness of time how durable it is! The tape is basically self adhesive aluminium foil also used for ductwork installations.



Having noted how tightly packed the cans were I followed suit.
Finally, wrapping it all really tightly with gaffer tape to compress it down to allow the sleeve to be slid into place. For the first can I found that I had slightly over done the wrapping as I had forgotten that the hanger fixing plate was going to impede the installation of the sleeve. It was a real struggle but we got there in the end, just!

When sliding the sleeve on pay attention to lining up the rivet holes in the flange on the inlet and carbon fibre sleeve as, depending on how tight the packing is, it is difficult to rotate the sleeve when it is nearly there.



Having assembled the can, sleeve and end cap it is time to fit the stainless steel band. Start in the middle and dry fit the pop rivets as you work towards the ends. Once all the rivets are in place you can begin to crimp them up.
I found that not all the holes lined up precisely enough to fit the rivet first time. This is where my tapered nail punch came in handy again as you can slide it in to the misaligned holes and gently joggle them into line sufficient to allow fitment of the rivet.

-------------------------------------------------------------------
The End Result

Before


After


Finally - The Hooligan Addendum

I was most dismayed when I found after only 7,500 miles that the cans needed repacking. If I had to do it again and didn’t already have the stainless steel rivets I would probably use ally ones and seal the opening in the rivet head with Araldite to prevent the head of the mild steel mandrel from rusting. But this does not deal with the, in my view, short service life of the packing. Therefore, in order to prolong this (time will tell) I took further steps to shield the wadding from the forces and extremes of temperature exerted by the exhaust gasses on it. When you see the fineness of the stainless steel mesh wrapped around the central tube you will wonder how the wadding disappeared. You can hardly stick a pin through the holes in it!

Therefore before I wrapped the tube in the wadding I wrapped it in many (many) layers of kitchen foil. Sealing it all up with the self adhesive aluminium duct tape.



But remember that the spigot in the end cap needs to slide over the end of the central tube so do not wrap it to the end of the tube.



The downside of this strategy (for the non hooligan element) is that the volume of the can filled with the wadding is then prevented from performing its function of sound attenuation and merely acts as a thermal insulant for the carbon fibre sleeve. Hopefully, stopping the brown discolouration. Therefore before I installed the rivets I fitted the cans to the machine and fired it up to assess whether or not they were too OTT. It was touch and go but by this time I did not relish the idea of stripping the sleeve back off and removing the wadding and then the foil. Compared to the standard DP cans they are LOUDER and totally AWESOME. On my first ride today I found that in built up areas you needed to be extremely gentle with the throttle and running as high a gear as possible in order to not draw too much attention. But people still turned their heads, hopefully in appreciation! On the open road you leave the majority of sound behind you but other road users were under no illusions as to your presence! Even the bike in front can hear you!

Materials Used

Stainless Steel Pop Rivets (Both rivet and mandrel are stainless steel and the rivets have closed ends to prevent the escape of exhaust gasses.)
Ducati Performance Stickers
Halford’s Petrol Resistant Lacquer.

[rockjock620]

nice work and good write up.

[barry]

Excellent stuff

[DukeDesmo]

Originally Posted by billywiztheelder

Nice writeup - but that's got to be LOUD.

[billywiztheelder]

Originally Posted by DukeDesmo

Nice writeup - but that's got to be LOUD.

Done about 300 miles on it now and they sound as though they have quietened down a tad. Thereagain I am probably just a tad more deaf!

Must give credit to Dan who bolted it all together at his end. It took him an hour. From my end it would have taken me all day!

[gillan900]

Great job Billy, and a very comprehensive write up.

The hardest part I found was the re-riveting, but I got there in the end and Chas's stainless steel straps were spot on.

[BaggaZee]

Superb write-up! Must tackle my own one of these days.

[marklestrange]

Good one- great help in sorting my termi shortie -
Does anybody know where I can get new stainless bands from? mine needs replacing.

[billywiztheelder]

Originally Posted by marklestrange

Good one- great help in sorting my termi shortie -
Does anybody know where I can get new stainless bands from? mine needs replacing.

Mark,

The man for the SS straps is chas, a top man, who knows a man if you get my meaning. I seem to remember they were about a fiver each plus postage. But he was making a few, so a one off may be somewhat more. Also he will need a one for a pattern as they are laser cut.

Barry

[bervie]

Nice one Billy, you've given me the confidence to do mine this winter. Can you tell me where you buy the padding from. Thnx.

[DukeDesmo]

Originally Posted by bervie

Nice one Billy, you've given me the confidence to do mine this winter. Can you tell me where you buy the padding from. Thnx.

Well judging by the 7,500 mile 'Hooligan addendum' I'd suggest you don't use that type of padding, rather motorcycle specific exhaust packing available from many on-line bike parts suppliers or bike shops, probably easier to find at motocross bike parts suppliers.

[billywiztheelder]

Duke, you have it wrong. The padding that didn't even last 7,500 miles is the original stuff that Remus built the can with.

The wadding that I have used is basically foil faced rockwool thermal/accoustic insulation used in drywall partitions that I picked up on one of my site visits.

Having removed what was left of the original stuff I don't see a lot of difference but time will tell.

[DukeDesmo]

Ooops, sorry Billy I had understood that you replaced the packing and then it failed, didn't realise that it was the original that failed so soon.

That'll teach me for 'skim' reading posts.

But to be honest when I repacked my Termis I wasn't much impressed with the way they had been done originally and I know that my repack will last much longer, I suppose they do what they need to and nothing more to keep the costs down - a bit like Ducati who simply 'build' an engine whereas an aftermarket tuner would 'blueprint' it, I suppose.

So to Bervie, as you were & ignore my comments although I personally would use motorcycle specific packing because I don't have access to anything else without buying it so I might as well buy the specific stuff, that said I bought a used KTM 500 Motocrosser which had been loosely 'converted' for road use some time back and that had the 'silencer' (I think trade descriptions might have had something to say about that term!) packed with attic-type insulation and I never noticed it breaking down but, in the words of my local MOT tester when I started it up at the test; "phook me that's loud!"...

[billywiztheelder]

Originally Posted by DukeDesmo

Ooops, sorry Billy I had understood that you replaced the packing and then it failed, didn't realise that it was the original that failed so soon..............

Duke, As you can see from the photos there is nothing wrong with the way they were originally packed as the tail end was in perfect condition. What amazed me was how did the stuff at the front end disappear as the fine mesh that is initially wrapped around the central tube (a few layers) is finer than a culinary sieve you will find in the kitchen.

As for what to use, I agree with you in that if you have to buy it then buy the proprietary product. It just happens that my profession takes me on construction sites where it is happily provided FOC (being the person responsible for certifying payment to the contractor!).

Barry

[vasco851]

nice post
great photos..

thanks a lot!