Cycle wing detached from stay!

[twincamtim]

Following a very bumpy bit of road earlier tonight the left hand side cycle wing has come unstuck from the top stay. From a quick look a black sticky substance has previously been used to attach it but I have no idea what this is.

I have tried a quick archive search but I could not find anything relevant - does anyone have some advice on what to use to re-attach the wing to the stay? NB - the wing is CF not GRP.

Thanks.

[Richard Price]

Polyurethane adhesive, such as "tiger seal" or "sikaflex" .

mine are currently fixed with the cheapest PU adhesive that I could find on eBay.

preparation is more important than the actual glue used.

[Richard Price]

Polyurethane adhesive, such as "tiger seal" or "sikaflex" .

mine are currently fixed with the cheapest PU adhesive that I could find on eBay.

preparation is more important than the actual glue used.

[Jonathan Kay]

I have tried a quick archive search but I could not find anything relevant

There's a vast amount on this.... more later. But not too much recently, which is interesting.

Here's a summary of what has been written by others and my experience, both of which are mostly with glass fibre reinforced plastic, rather than carbon. It's consistent with Richard's post above.

1. It is possible to get good fixing with goo alone. 
2. Most people use a Sikaflex product but there are lots of different ones. I haven't seen a decent comparison between them or with Tiger Seal, but the latter seems to have some adherents. (!) Possible sources of the right Sikaflex product are body shops and marine chandlers.
3. Preparation of the stay is crucial, and rubbing back to bare metal is recommended. I don't know if priming and roughing after that is a good idea or not. I didn't.
4. Preparation of the wing is also presumably important. I just cleaned mine, finishing with isopropanol, but NB that wasn't carbon fibre reinforced plastic.
5. It's better to make a sausage roll around the stay than a sandwich.

Jonathan

[Jonathan Kay]

I have tried a quick archive search but I could not find anything relevant

I don't use the internal search, here's what I came up with using an external search engine with site restriction:

https://www.google.co.uk/search?q=site:lotus7.club+fix+wing

https://www.google.co.uk/search?q=site:lotus7.club+sikaflex
​(and that identifies opinions about the best Sikaflex product).

​Jonathan

[twincamtim]

Many thanks for the responses.

Jonathan - I have not tried that search method but will do so from now on (the internal searches are usually very frustrating!).

[Manstein]

I recently used Sikaflex 291i which did the job but as stated the preparation is important.

[twincamtim]

Just on the preparation, what is the best way to clean the CF prior to adhesive - denatured alcohol?

 

[Jim 123]

Are there any clues as to what came unstuck? i.e. Glue to wing / glue to wing stay / or adhesion failure of wing stay powder coating to substrate. From memory Daniel French did a good description in his build blog of using BigHead fasteners which may be worth a look if you haven't already considered going that route.

[BigCol]

As above...  preparation is vital as the adherence of the powder coat to the wing stay is nothing like as good as the Sikaflex to the powder coat - so remove the powder coat and bond to the metal of the wing stay!

As Caterham recommend (sell!) Terrostat 9220, that's what I used - best price is from RS (always "Irish" in my mind) Components.

[twincamtim]

Jim 123 - a mix of both glue to wing and glue to wing stay. I didn't spot a big pothole and the impact just seemed to break the adhesion of the glue! It is black and sticky but not much of it - more a sandwich than a sausage roll (thanks to Jonathan for that analogy!). I will check the blog you mention.

BigCol - thanks, I'll check that out.

[Colin Cooper]

I tried all of the above, was very careful with the prep, put loads of stuff on - but they have both come off again.

Now bolted the buggers on. just let them try.................................

[Jonathan Kay]

Which adhesive, and where did it fail, please?

Thanks

Jonathan

[BigCol]

The advice I got when I built mine was... clean the powder coat off the stay; clean it thoroughly; clean under the wing thoroughly; put a thin line of bonding on the stay and fix the wing; when dry, add more bonding around the edges and smooth with a wet gloved finger.

Worked a treat for me - no issues with original wings or the carbon ones I've fitted subsequently.

Some people prefer Tiger bond but the principles are the same - don't trust the powder coat and clean thoroughly...

[Jonathan Kay]

Some people prefer Tiger bond...

Isn't that Tiger Seal (from U-POL, a one part polyurethane) rather than Tiger Bond (from Beacon, probably a cyanoacrylate)?

Jonathan

[BigCol]

Jonathan Kay said Isn't that Tiger Seal rather than Tiger Bond?

Good question...  in all honesty, don't know!

I've only ever used the Terrostat 9220...!

[Tony Whitley]

Most people use a Sikaflex product but there are lots of different ones. I haven't seen a decent comparison between them or with Tiger Seal, but the latter seems to have some adherents. (!) 

I think I'll stick with Sikaflex 

[Jim 123]

From my research during the build Sikaflex 292 is believed to be the best product.  It is a marine adhesive and a bit more expensive. 

[Jonathan Kay]

Several of us used Sikaflex 221 black and were happy. As above, I don't know of any informative comparison tests.

Jonathan

[Jonathan Kay]

I've only ever used the Terrostat 9220...!

TEROSON MS 9220 (Known as TEROSTAT 9220): That's also a one part polyurethane. Don't know the significance of it being "silane-modified".

They recommend their proprietary cleaner: TEROSON VR 20 (Known as TEROSON FL+), which is "white spirit based".

Jonathan

[David aka Blue7]

Some good advice given above.  I have had 3 cycle wings come off my CSR and had lengthy conversations with CC on the subject.  Basically they told me that they use windscreen sealant to secure wings to stays ... don't get me started but they say this should be adequate but IMHO there are three irritating problems

1. CC will not accept that it is a common problem despite the fact that I have provided BC discussion links

2. They are using the cheapest bonding agent and it is not fit for purpose ... IMHO

3. Preparation is "carp", the end result is always the same, the bonding substance always adheres to the stay but detaches from the cycle wing.

In the past I had great success with Tigerseal but it is somewhat "drippy" so you need to defy gravity by holding it in place with cling film.  Best solution is as mentioned Sikaflex and as a belt and bracers solution I also used big head fasteners with industrial cable ties but also as stated ... you could consider using fiberglass to bond the wing over the stay.

I understand that Mclaren use a bonding agent to bond body to chassis and I have in the past suggested to CC that they consider using such a substance instead of windscreen sealant but they don't seem too bothered about what happens to the cars once they have sold them. 

On a recent June event at Inver Lodge (Scotland) with LADS and Scotland North members, two cars lost a cycle wing.  I would support an official representation from L7 Club to CC complaining about this problem that CC refuse to acknowledge.

[ScottR400D]

I did something in between. 

The forward stay, I used 3 35 x 15 studded bigheads. Line these up on the stay and drill three 6mm holes for them to go through and bolt them on, with masking tape under them around the stay. Prepare the underside of the wing (mine are carbon) by cleaning and abrading. 

Sikaflex on the bigheads, press the wing on in correct position. Tape in place until cured.

Once cured, remove the nuts on the bighead studs and the wing can be removed, the bond inspected and built up if necessary and the masking tape comes off the stay with any stray Sikaflex.

You obviously can't do this on both legs of the stay if you want the wing to be removable. I simply bolted the wing to the rear stay with black bolts, they're hardly noticeable. 

For me the advantages are that you don't have to take the coating off the stay, the wings are removable and the top of the wing is bolt free. 

The bond strength based on sikaflex data for the materials and area in contact is several hundred Kg, not counting the extra strength due to the bighead holes. 

They've been on for 2.5 years now and the bond still looks fine. 

 

[twincamtim]

Right, I have used Teroson 9220 (an 80ml tube is just over £5 from RS Comps) and will be testing it around tea-time today!

I cleaned off all the old black gunk (which to be fair could also have been Teroson although it was grey not black) degreased the surface of the arms (which had previously had the black paint removed) and then applied the Teroson. It went on easy, sticks well and doesn't run.

I had plenty of time to create a partial sausage roll effect before it started to skin over (approx 6 mins). It takes 24 hours to completely cure so we'll see how well it works later......

[anthonym]

gosh how times change. I had this problem, which is duly documented in techtalk I guess now lost in the old system/blatchat.

so, back in the day, the received wisdom was NOT to glue things directly to the stays. In short the solution was and mine still continues to be since.. so long I forget and my wings are easily removable and haven't come off or loose:

Sikalflex (I have no idea which, maybe I can find it), though I suppose any suitable adhesive.

Bigheads two per stay, 

Cable ties - easy to fit and easy to remove and refit, two small ones per bighead.

Sikaflex bigheads to cycle wings (Carbon Fibre, I was told very firmly to make sure they were clean prior to application)

 As such removing my cycle wings is trivial, and very nice to have when doing various things.

Recently when removing and refitting my cycle wings I noticed in the past I have used some double sided table laid along the stay before resting the bigheads on them, whether that ever actually did any good I cannot say, perhaps vibration amelioration. This time I have not replaced that tape. 

Rereading the above there's clearly a matter of aligning/placing the bigheads so they line up with the front/rear stays and across each stay. Don't recall how I did that.

Anthony

[Tazio]

What he said.

Big Heads and tie wraps for me....haven't come off yet....