Depending on how you store your glider, your MKIV yaw string should provide many hours of carefree soaring, free from that embarrassing "kluged tape on the canopy syndrome". How long? Anywhere from a few years to many more than I wish (planned obsolescence and repeat business being part of my retirement business model :c). When it's finally time to put a pretty new one up front, it's easy . . .

These instructions are for use if you're happy with the current position of the MK## yaw string. If not, please refer to the new installation instructions available at http://www.cumulus-soaring.com/bumper.htm or http://www.williamssoaring.com/catal...ane-parts.html or from me via email (below).

Please remember MKIVs and QVs make great Christmas presents. Your friends will be reminded of how truly nice you are to them every time they fly!


At or above room temperatu

The MKIV clear base is "V" shaped with pointed end facing forward. Apply masking or wing tape to form a "V" parallel to and close to each straight side of the MKIV base. The taped "V" will serve as a guide to aid in positioning the new MKIV.

With your fingernail or the tip of a knife blade* being careful not to touch the canopy plastic, lift the leading edge of the old MKIV base and pull back to remove. The plastic base with adhesive layer will usually come off cleanly, leaving no residue behind. If the adhesive layer or any residue remains on the canopy, rub with your thumb roll it off cleanly.

*If using a knife blade, catch the tip of the old base slightly above the canopy surface so as to avoid any risk of scratching the canopy.

Clean area within the taped "V" with denatured or rubbing alcohol applied sparingly to a soft clean cloth. Hold the new MKIV by the yarn or by the base edges and use a knife tip to lift the red backing film starting at a rear corner of the base - be careful not to touch exposed adhesive with fingers.. Peel away red backing and then re-apply pointed tip of backing to form a "handle". The pointed tip of the red backing overlapping the rear of the exposed base adhesive about 1/8" or a little more.

Holding base with red backing "handle", and using the taped "V" as a guide, place the tip of the new MKIV base centered within the apex of the "V" maintaining even gap from base to tape on each side - - do not allow MKIV adhesive to touch tape. You get only one chance to get it on straight, once adhesive touches canopy, removal and reapplication won't look nice.

With tip in place, and holding rear of base up at 30 degrees or so with red liner handle, use finger nail or retracted ball pen tip (something smooth)to gently work adhesive down toward rear to avoid bubbles. Red liner can be pulled aft to remove before rear of base is smoothed down. Apply even downward pressure to base for a few seconds. Adhesive gains full strength in 24 hours but is ready for flight immediately.

Do not store your new uninstalled MKIV yaw strings or Quiet Vent kit in direct sunlight or high temperatures (e.g. on the dash of a vehicle) as this will degrade the red plastic adhesive liner making it difficult or impossible to remove (return for free replacement if you've already screwed up).

all the best,

bumper

bumperm at frontier (insert dot here) com
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Minden, NV