Looking for a rivet band for a Sil Motor oval carbon can.

[Darkness]

Originally Posted by utopia

Darkness .. the central perforated tube is tapered, so cutting anything off either end changes its terminal diameter and then the endcaps wouldn't fit.
In fact one end has already been shortened by about that much and I have had to thin down the inner tube a little to restore the fit with the endcap. I'm not sure that there is any scope for further thinning without overly weakening the tube.

If the taper is something like 20mm in 400mm of length, the change in diameter from cutting off 10mm would be something like 0.5mm. Are they really made to that level of precision?

[utopia]

Dukedesmo .. that could well be the solution I'm looking for.
And I will need to buy rivets anyway, which will cost around a tenner, so that price doesn't seem too bad to me.
Thanks.

Darkness .. As best I can measure it, the diameter would get bigger by about 0.4mm if I cut 10mm off.
I agree that's not much, but it needs to be added to the minimum of 10mm or so that I estimate has already been cut off.
Thus the total effect would be 0.8mm on the dia, meaning a 0.4mm reduction in wall thickness of the perforated tube.
Again, as best I can measure it, the wall thickness of the perforated tube is only 0.5mm to start with.
Its a lot more marginal than you might think.
Tbh, that's tighter than I thought it would be until I measured it just now.
Also, the length of the can sleeve is only 270mm, which I already consider to be a tad short really, so I'm reluctant to cut even 1mm more off it.

[bigredduke]

Have you tried this supplier?
http://www.aa16.co.uk/store/cgi-bin/cp-app.cgi

Careful with that C1, we had one for the girls to learn to drive in. 0 - 60 eventually.

[Flip]

Jeff for the cans I’ve refurbished I’ve use these for the rivets:

https://rover.ebay.com/rover/0/0/0?m...2F310463748209

If you haven’t already got a decent rivet gun it’s worth the investment for stainless rivets as they can be pretty tough on the usual style hand operated ones.

Exhaust bands I’ve drilled myself from bought cut strips- loads of suppliers on eBay.

Don’t forget if using a carbon sleeve to line it with some heat reflecting tape or it’ll burn if it gets a ‘hot spot’ as the sound proofing ages.

https://rover.ebay.com/rover/0/0/0?m...2F303207108234

Finally for wadding I am a big fan of Acousta-fil:

https://rover.ebay.com/rover/0/0/0?m...2F360974388595

[utopia]

Thanks for that, Phil.
I had already planned to use acousta-fil, following your recommendation a while back.
Presumably, since the acousta-fil expands to fill the can, it would be necessary to line inside of the carbon sleeve rather than wrapping the fill with heatproof tape ?
Mind you, the old fill was completely burnt away for about 2/3 of the length of the can when I dismantled it, without any signs of burning ... but I'll line it on rebuild anyway. I have some plain aluminium tape that I was thinking of perhaps using but maybe something like you suggest with a fibreglass layer would be more appropriate.
And lastly .. excuse the daft query but just to be sure .. when they say stainless rivets they do mean that just the core is stainless and the main rivet body is aluminium, don't they ?

Interesting to hear that you have successfully drilled your own rivet bands.
I was anticipating that they could easily snarl up as the drill broke through on such thin material.
I was thinking that I might use a centre-drill instead and perhaps finish to size with a taper reamer or a file.
Did you use a normal twist-drill ?

[350TSS]

I would have thought you can drill the SS if you clamp it in the vice between two bits of sacrificial 6 mm aluminium plate

[utopia]

Originally Posted by bigredduke

Careful with that C1, we had one for the girls to learn to drive in.
0 - 60 eventually.

Yeah, its a beast alright.

Actually, I was pleasantly surprised at how well it drives and how it doesn't particularly handle like a small car.
But then, when I'm on four wheels I'm not that fussed about performance.
And at £20 per year tax, it can sit on the drive doing nothing most of the time without costing me too much money.
As cars go, I actually rather like it.

[Dukedesmo]

Originally Posted by utopia

And lastly .. excuse the daft query but just to be sure .. when they say stainless rivets they do mean that just the core is stainless and the main rivet body is aluminium, don't they ?

Probably not, full stainless rivets are a thing and they are very good and (unnecessarily) strong but you need a heavy duty rivet gun to fit them and they are a pig to drill out if/when you want to remove them.

Best to use aluminium on a carbon can IMO as future servicing may well see you damaging the carbon on removing the stainless rivets...

[utopia]

Originally Posted by 350TSS

I would have thought you can drill the SS if you clamp it in the vice between two bits of sacrificial 6 mm aluminium plate

Yes, that was part of my thinking too.
I probably wont be exactly sure how I'm going to do it until I actually make a start.
You know how it is.
One problem that I foresee is that the vice might get in the way of the drilling operation.
And I would prefer to drill it on my little drill press if I can, rather than offhand in the bench vice, but then the clamping becomes even more tricky.
But thanks for the input.

ps.
Fortunately, I inherited a number of taper reamers (for finishing the holes for taper pins) from my father.
I fancy that these might come in handy, enabling me to drill the initial holes quite small and then enlarge them afterwards with said taper reamers.
.... hopefully.

[utopia]

Thanks again, Tim.
That is both handy information and good advice, I reckon.
Looks like I need to source some blind, aluminium, gas-tight rivets.
The original rivets were aluminium bodied but with stainless pins, and were fairly easy to remove by simply drilling off the aluminium heads.

[bigredduke]

When I cored the cans on my S4R, I used SS rivets to secure the end caps. Although they are a bit harder to "squeeze" into place I just used a normal rivet gun. I have some left, how many do you need?
The rivet body is 3.94mm dia, 9.82 length, rivet cap is 7.72mm dia. Total rivet pin length is 43.42mm. As far as I can tell, both the rivet body & pin is SS.

Fair point about using them on carbon sleeves though.

I didn't have any issues with exhaust gases leaking from the rivet head, I guess they take the path of least resistance through the normal outlet.

[hhmunro]

Drill speed is very important with drilling stainless, check which stainless it is, information on the WWW, and use a lubricant...

[Dukedesmo]

I didn't bother with blind rivets as I had plenty of the normal kind laying around plus, I think if it starts blowing gases through the rivets then it's a sign that you need to re-pack anyway!

I wrapped the entire package of wadding with aluminium tape - there are several benefits to this;

You can 'form' the correct shape for the can, making it easier to insert.

Slides in easier as there is no wadding to snag on the sleeve

Adds an extra layer of heat protection to the carbon once the wadding has burnt out.

Termignoni only use a couple of wraps of paper masking tape but I suspect this is to keep the cost and assembly time down rather than best practice.

If there is not already some in there use some SS gauze around the perforated tube before wrapping the wadding as this helps protect it (Termis have this, not sure about others?).

[Flip]

Originally Posted by Dukedesmo

I didn't bother with blind rivets as I had plenty of the normal kind laying around plus, I think if it starts blowing gases through the rivets then it's a sign that you need to re-pack anyway!

I wrapped the entire package of wadding with aluminium tape - there are several benefits to this;

You can 'form' the correct shape for the can, making it easier to insert.

Slides in easier as there is no wadding to snag on the sleeve

Adds an extra layer of heat protection to the carbon once the wadding has burnt out.

Unfortunately you can't really use this method when using Acousta-Fil as you pack it quite loosely because it expands when heated filling any gaps in the process (you can actually hear the can has got quieter after it's first proper hot run up).

Acousta-Fil ready to go in:



So after giving the inside of the can a wipe over with some IPA (Isopropyl Alcohol) I then use an adhesive aluminium or aluminium glass mat tape stuck to the inside of a carbon can to protect it and because Acousta-Fil doesn't fill (sorry for the pun) the can initially there is no real problem when putting it all back together.

Again, when re-assembling I also smear a light coat of clear RTV silicone sealant on the faces where the can meet the inlet and exit spout just to ensure there are no leaks (a fussy MoT inspector could fail it for not being gas tight even if he accepts the volume- stupid I know but there you are) then I finish it off with blind rivets.

All the cans I have done, whether stainless, alloy or carbon have all had stainless steel gas tight rivets used so it seems logical to use the same when re-packing them and because the carbon is essentially 'sandwiched' between the metal spout and the rivet band it doesn't do any harm in my experience.

Gas tight stainless rivets compared to open aluminium ones:



As for drilling them out I use a 7mm Dewalt Cobalt drill bit in my Makita cordless drill- it takes the heads off nice and clean and then I simply tap out the rivet body with a correct sized punch.



They go through Stainless like butter:


For drilling the bands I make a mark and centre punch where I want to drill and go up in 0.5mm increments from 1.5mm (the smallest my cordless drill chuck will take) until I get the size I need and I just hold the band with a pair of pliers and drill into a piece of wooden block.

A late 80's Micron for a CRMC race bike I am doing, notice this is an alloy can with a chromed steel spout and no bands were/are used for this combo:



A 1990's MIG race can I have salvaged for my Yamaha Thundercat which is slightly unusual in that the inlet is Stainless Steel and is also the link pipe (like our Monster's) while the spout is alloy and the can as you can see is Carbon:



Finally the rivets on the FBF cans on my Monster after their re-packing:

[Darren69]

So just send your cans to Flip and he'll repack and sort 'em for you!