Bigheads & FS Adhesive Failure - Any thoughts/solutions

[Gregs79]

Hi all,

After returning home from a 3,500 mile tour of Euro over 2.5 weeks following Le Mans we had an incident whilst on holiday where the adhesive used to hold my wings on failed. 3 of the 8 Bigheads detached themselves loose, 2 on the near side wing and 1 on the offside. Duct tape saved the day for the rest of the tour, but now I'm back I would like to re-attach them using the same methodology, but looking at a different adhesive, any thoughts?

Silkaflex or Tiger Seal seem to be the favoured options, but there are a mix of opinions on which to use?

Has anyone else experieced a similar issue with adhesives failing? 

Kind regards

Gregs

[Jonathan Kay]

Yes, there are lots of reports of failure of adhesion. It's a classic evidence-based problem: strongly-held beliefs with few good studies, most of which are "Try different things until they don't come off", arguments based on plausibility, reliance on authority, and possible underreporting based on embarrassment*. And our own reports scatttered across multiple threads. But that's all we've got.

From what I can tell from extensive study of the archives and my very limited experience the most reliable solution if you don't want the wings to be easily removable (when you choose) is:

• Clean and degrease contact area of wings
• Take stays back to bare metal
• Either prime the stays or don't 
• Use Sikaflex 221** (there are lots of types) make a sausage roll around the stay, not merely a layer where it contacts the wing
• Fix.

Jonathan

* And lots of admirable humility.

** There are advocates of Tiger Seal, and it is cheaper but I'm not interested in saving money in the solution: I've already lost a windscreen through failure. But there was a discussion about why Sikaflex is preferred, and whether it is just brand-dominance.

 

 

 

[NedK]

I spent quite a while setting Bigheads up on my new build - following the excellent R500 blog by Daniel. Same thing happened to both of us: Caterham covered them over with Sikaflex during the PBC!

 

[Gregs79]

Thanks for the info gents. :-)

[Golf Juliet Tango]

I think my solution is to bolt through. Button head and a washer.

[7 wonders of the world]

Ditch the bigheads and Tigerseal them onto the stays - job done.

[RS2000]

Tigerseal bonded nearside front wing that I did myself has to date lasted 4 years, the offside that Caterham Midlands did gave up the ghost after 3 years - I don't know what they use as standard, but I suspect that it was probably more the quality of their work rather than the product used...

(and the bonded bigheads used to attach the mudflap on the 'caterham' side also disappeared around the same time...)