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Replacing TE Velcro on a VR

PostPosted: Mon Nov 23, 2015 1:04 pm
by nev
I'm about to get the Velcro replaced on my VR (trailing edge).

Nigel (at Topflight, Wales) hasn't done a VR yet, and wanted some photo's and question whether both hook/loop need replacing, or just the loop (i.e. the softer half where the mesh gets broken)

After having trialled some pieces of 'loop' on my 11 year old glider, it confirms the 'hook' is OK and hence looks like just the loop side needs replacing.

It looks like there are 2 separate velcro sections on each wing half

The 1st section (from the flap outwards) is a simple replacement of loop velcro (on the top sail).

The second section (the Flap section) has a removable 'strip', and has 3 surfaces to join lower & upper sails and flap. One surface of the strip sticks onto the lower sail, onto which the flap sticks too, and then the 'other' side has the 'loop'. It looks like the removal of the loop (prior to replacement) will be an absolute pain, and was wondering if anyone has simply oversewn loop Velcro onto the existing loop Velcro? (the worn Velcro is probably only 2mm deep anyway). Given the sail probably only has another 5 years (I said that 5 years ago), it may be the best cost/benefit approach.


Re: Replacing TE Velcro on a VR

PostPosted: Thu Nov 26, 2015 2:48 pm
by Martin
Nev, When I upgraded to the Technora sail, I ordered a the flap section of Velcro from AIR... I glanced at old price list, about 150 Euro for a pair. Odds are, to sew onto the adapters they will have to be pulled off of the flaps and getting the finished results to be clean and straight will be a real challenge (and a few broken needles and quality cuss words ;-). If you end up pulling the adapters off you might want to look at the Velcro on the flaps... now that project is a real pain! ;-) Takes forever to pick off the old stuff and bucket of Acetone to clean up the glue. Truth is I found just the ends tend to wear out, so you could just fix up a short section and be done with it... or just leave it alone. FYI, if you have some wavy looking flaps, it would be a good time to take out a heat gun and straighten them out... or not.

On the outer section, I've always had trouble avoiding getting twist in the trailing edge when trying to refresh the Velcro. It's the side effect of trying to sew new stiff Velcro onto soft old Dacron. Normally you would cut relief darts along the luff/cup of the TE Velcro and tape in place (pretty much stock). Last summer I updated a short section on my tips and decided to use a wider then stock Velcro (I think 36mm wide), then cut the luff/cup into the Velcro. The end result was the Velcro and sail ends up perfectly flat.

How many hours on your sail? Do you ever dream about pulling the zipper open on a brand new bag?


Re: Replacing TE Velcro on a VR

PostPosted: Fri Nov 27, 2015 9:49 am
by nev
Thanks for the detailed reply Martin.

How many hours on your sail? Do you ever dream about pulling the zipper open on a brand new bag?

Probably around 600, but as I haven't been near rock-strewn launch sites its generally in good order, just a few nicks.

The new zipper will be opened sometime between 3 months and 15 months; timing involves a delicate balance of recently reduced outgoings (son just finishing expensive private schooling), redundancy from early May (Yippee!), and not wanting to cash-in chunks of pension until some time-dependant investment gains have been made. I'm in contact with our UK AIR dealer, and in the last 4 weeks the delivery window for the VR+ has gone from February to May, which is pretty much too late. My remaining hope is the demo VR+, otherwise I'll need to tease the old girl through 1 more season. Its a real struggle of mind having to overcome emotion, as I just know what that VR+ will be capable of..........

Back to Velcro - yep, looks like the inboard/flap section needs the 'new' removable strips, as well as the Velcro that sticks onto the flap.

For the outer section, I'm getting Nigel (at Topflight) to do the work on the outer section; he's been a sailmaker since the early Hiway days (late 1970's and Scorpion/Super-Scorpion), and has a reputation for excellent work.

I'm also having the holes (for the Spoileron mechanism) widened, as with shrinkage both of mine are migrating inboard .....currently a little bit of conflict, but the arm always seem to 'ping' through.......

Re: Replacing TE Velcro on a VR

PostPosted: Tue Dec 01, 2015 5:06 pm
by nev
Right, all parts ordered & sailmaker scheduled in January to replace the outer Velcro

Any advice on how to reassemble the new flap/Velcro strip, i.e. the 3-way velcro strip that joins Flap+Lower TE (permanent) & upper TE (when rigged). Do I reattach the flaps with the sail still off, or is it easier when the glider rigged (with the sail taught & in position); I'm guessing the latter?

Also, my flaps are in slight 'conflict' at the centre near the keel, I'm suspecting this is due to sail shrinkage, so I'm assuming I just need to reposition the flaps further outboard during the reassembly? (I can't image a change of wing sweep having caused the issue, giving the fixed nature of the D boxes and nose catch)

Thanks in advance for any advice!

Re: Replacing TE Velcro on a VR

PostPosted: Wed Dec 02, 2015 12:36 pm
by Johnnybravo
Nev, Way back I took one flap off to undertake a repair. Before removing it, I marked(longitudinally and laterally) the position with black marker pen at various places along the length so that it would go back in the same place. I am sure moving it along would be fine, but make some new marks all moved by the same dimension. When you reattach the flap you mask off the velcro with low tack masking tape and as you reattach the flap you put the masking tape out, otherwise you will get into a mess with the velcro reattaching where ever it touches . I cannot recall if I reattached the flap on the rigged glider. I guess it would be easier if the sail was off and on a long flat surface (I think that is what I did in the end).

Re: Replacing TE Velcro on a VR

PostPosted: Wed Dec 02, 2015 4:03 pm
by nev
Cheers John

Good tip on masking the velcro to allow a controlled application........ (I do something similar with double-sided tape on Bluefly Vario's, to get the PCB inside something that is almost the same size - double sided tape doesn't like sliding!)

I think I'll try 'flap off' first, as its a zero-cost option (I can only fail!), plus I can do it indoors.............I thought I was going to have to hire a (dry) village hall