carbon fibre onto mild steel

[comet]

Hi all,
I am after some advice please.
I know if I were to use carbon fibre and aluminium together I would need a barrier between the two, be it glass fibre matting or possibly to anodise the aluminium part. Is the same true of using carbon fibre and mild steel? I have been given an old bicycle frame ( pretty sure it is steel and not chromoly mostly due to its age and weight) that is a bit bent and very much past its best so I was thinking of replacing a couple of the frame tubes with carbon fibre, but I have absolutely no experience of using carbon.
Any and all advice is welcome.
Thanks all in advance.

John

[Doc B.]

Maybe you already googled this, but in case it didn't come up for you -

https://www.velocipedesalon.com/forum/f10/bonding-carbon-fiber-tubes-steel-lugs-41794.html

[comet]

Hi Doc,
thanks for the link. I hadn't seen that one before. Still not sure it really gives me an answer, but it sounds like a layer of glass fibre is probably more than just a bit sensible between the CF and the parent metal to prevent the corrosion.

cheers
John

[Doc B.]

My business park neighbor does a lot of CF work, including carbon fiber wheelie bars. I'll see if I can get any insights from him.

http://www.beckengineering.com/store/c4/Carbon-Fiber_Wheelie_Bars.html

[Speed Limit 1000]

the problem is the carbon makes a resistor and galvanic corrosion will cut almost any conductive part even stainless. You use epoxy to insulate the carbon. Yes just a thin layer of fiberglass will work

[edinlr]

When I was at PRI last week I did take a look at the CF driveshafts.  One booth showed how they tried using a metal male end with grooves running long ways to hold more epoxy.  It failed and they went with a fairly smooth machined end and epoxied it to the CF for a strong bond.  If these drive shafts will hold 1000 hp, you should not have much trouble doing this for bicycle parts.  A little research into CF driveshafts will probably answer all of your questions as to surface and adhesives.  I did see shafts with both aluminum and steel parts bonded with CF, so it would appear that both metals would work for your application.

One of the exhibitors last week was Rock West.  Their staff was very nice and they also carry the tubing you need.  I am pretty sure they could explain the methodology in depth.  https://www.rockwestcomposites.com/