Best surface preparation for SS to bond with epoxy adhesive to carbon

[Onda]

I should bond a carbon resin tube to a stainless steel tube.
(the carbon tube is outside and the SS tube is inside).
I would like to know the best surface finishing for the SS tube to obtain the best strength in the bonding.
I will use to bond Gurit SP System Spabond 345.
I would also know wich difference in diameter I should keep to obtain the best strength.
Inner diameter of carbon tube is 45mm, and I was supposing a Outer diameter of SS tube of 44.5mm.
Maybe this subject has been treated but i couldn't find anything!
thanks

 

[MintJulep]

A typical surface prep for stainless steel would be:

Degrease.

Etch in a hat witch's brew of oxalic acid, sulphuric acid and water.

Brush off the black stuff, wash in water, dry and bond.

As for the rest, you haven't given enough information to allow anyone to give you a useful suggestion.

 

[Onda]

MintJulep,
thanks for your reply,
This the data missing:
Carbon tube:
Outer diameter 64mm
Inner Diameter 45mm
Laminate: 80% +-45°; 10% 0°; 10% 90°

AISI 316 Tube:
Outer diameter 44.5mm
Inner diameter 29mm

Length of bonding 60mm.

The tubes are loaded only in torsion.

About surface preparation:
It is better to have the steel tube knurled or a smooth surface?
In the case that is better a knurled surface, which deep the pattern should have?


thanks

 

[CoryPad]

A roughened surface should work best. This allows mechanical bonding of the adhesive in addition to chemical bonding.