I did some test samples before committing to the Poly-Fastener change.
Test 1:
I tried "roughing up" the back side of the channel with some sandpaper and applied a thick epoxy glue to the back side. I then screwed it down to a piece of 3/4" plywood and allowed it to fully cure. Once cured I removed the screws and abused the material trying to get it to release from the plywood... Didn't take much... The glue joint failed very abruptly and the piece came away from the plywood very clean with no apparent traces of the epoxy on it at all.
Test 2:
Same scenario... different glue. This time I used "3M 5200 Marine Adhesive/ Sealant". Same abuse, more abuse, still MORE abuse... it's still stuck even after being wailed on with a 5 lb mash hammer.... I'm convinced- It's NOT coming off easily- and remember... I removed all the screws!
Test Sample stuck forever to plywood.
Test 3:
I made a small mock up using the Poly-Fastener 800, and 3 of my finger skirts. I just screwed the Poly- Fastener to a piece of plywood set at the approximate angle of my hull- No glue this time- just a 1/2" flat head sheet metal screw every 4".
Channel screwed to the plywood.
Because the Viper uses individual finger skirts I needed to cut the insert strips to the same length as my original skirt battens- about 4" long.
Insert strips cut to size.
I inserted the strips into the finger skirts and attached them into the channel.... Basically the skirts won't let go!. I really think you would rip the material first! I took a 35lb concrete block and clamped it to just one of the skirts! ( remember in this situation I am using a insert strip that is only 4" long ) I let it hang for approximately 30 minutes.... and then the clamp slid off of the material. Poly- Fastener is GOOD stuff and I think it is going to work out much better than the original skirt battens!
3 skirts hung with Poly-Fastener 800
Back side of skirts
Skirt with 35lb concrete block attached.
While I'm on the subject of plan changes I've made a couple of more. You already know my dislike of using sheet metal or wood screws for items that need to be removed. The instrument panel, panel covers, and engine cover all fall into this category. I decided to go the "Homebuilt" airplane route and use an item called "Rivnuts". Rivnuts install like a "pop rivet" , but leave a threaded hole. I am using Rivnuts that have a 10-32 thread.
Rivnut installed in 3mm Marine Plywood
Back side of Rivnut.
Typical application.
My next variance from the plans is on the rub rail/ collision strip that runs around the perimeter of the craft. I ordered the rub rail from Nell Fabrication. The instructions require aluminum to be bent to the proper angle and then epoxied to the craft. The rub rail gets epoxied to the aluminum angle. Frankly getting the aluminum bent to the proper angles, attaching it to the craft, and then attaching the rail to the aluminum seems like a LOT of work! During my testing with the Poly-Fastener the 3M 5200 Marine Adhesive / Sealant worked VERY well, and after checking a few sources I found that it is used for commecial rub rail installation as well. I made up a test sample and glued a piece of the rail to the edge of a piece of wood- holding it in place with some fiberglass reinforced packing tape.. allowed it to cure, and went into full attack mode.... I was wailing on it with a 5 lb mash hammer and it still wouldn't come off- and this was a small sample which didn't allow the impact load to be absorbed by surrounding material. Cool... I know what method I'm using... and it doesn't include any aluminum!!
Rub rail test sample
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