sealing kits

[duzgis]

Hello,

A general question:
Do you have any feedback or comments regarding the control gap sealing kits from

 http://www.streifly.de  ?

Would you recommend the standard kit or the one with combi tape for a PIK-20D glider?

Thanks in advance!

[David Sutton]

I had a Streifenader sealing kit installed on a my 20E over 20 years ago. It was a lot of hassle: The engineer informed me that it would be subject to a modification request. The UK CAA insisted that it would be a major mod, which would have been nigh on impossible to get approved in practice. In desperation I scoured the TRAFI website to see if an approval had been made in Finland but ultimately got so deep into the website that I was presented with a warning that the content beyond that point was all on Finish, but helpfully gave me an email address to further my enquiry. I emailed my question and within a day, received a reply from the Finish Head of Flight Safety, who informed me that no, such an approval had not neen made in Finland but that in his opinion, it was a minor mod. I then asked my contact at the CAA if he would accept the opinion of the Head of Flight Safety in another EASA-regulated country, and he said he would, so I sent him the email. The work was reluctantly acceped by the CAA as a minor mod and went ahead. The Streifenader kit was supplied without PTFE anti-friction tape and was installed as supplied. The ailerons were so stiff that the aircraft was unflyable. The engineer then retrofited PTFE tape on the upper and lower leading edges of the flapperons. The level of friction was much lower and the aircraft quite flyable, but the controls are still far stiffer than with cloth seals. It looks neater, but there was no discernible increase in performance / handling. Also, the leading edge of the lower capping tape near the tips is prone to damage when taxying (this would be less of an issue with a 20D). The problem, I suspect is one of length - with tthe flapperons there is 2 x ~15m of contact area between the wings and flapperon, whereas with separate flaps / ailerons the individual contact areas would be much smaller and therefore subject to much smaller frictional forces.  If I had to do the job again, I would go back to cloth.

I'm sorry that this isn't a ringing endorsement but hope it helps.

David G-BHNP

[Bill Mileski]

I used their kit suggested for the Pik-20B and had no issues. Included the anti-friction teflon tape. Controls remained low effort. 

However, was a little surprised that the kit did not include or suggest the thin flexible tape that positively closes the path of air from top to bottom, if you understand which typical piece I am speaking of. So basically air can sneak past the outer seals’ trailing edges and proceed to the opposite side of the wing.  Not sure if their kits for the other variants of the Pik-20 are similar. 

Bill

On Mar 12, 2026, at 1:25 PM, 'David Sutton' via PIK20 <pi...@googlegroups.com> wrote:



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[David Sutton]

Bill,

"

"...So basically air can sneak past the outer seals’ trailing edges and proceed to the opposite side of the wing...." - that might explain some advice I was given at the time, which was to leave the cloth seals in place if possible (it wasn't...).

David

[John Mills]

We made seals from offcuts of cloth used for spinnakers from a sail maker and used a good adhesive.  It's good for pushrod seals too.  For the flaps we found a durable, flexible, sticky medical tape.
John Mills
PIK 20B

To view this discussion visit https://groups.google.com/d/msgid/pik20/e7f12fa4-68ce-4b13-b815-ceb1968ba86an%40googlegroups.com.