The front stab. screw insert is slowly pulling out of the fuselage on my AFS W95 foil, it is tight, stab. is locked in, but I have hit bottom occasionally and other things. Wondering if I can just screw it back in, or need to remove and epoxy back in. The original screw inserts were molded into the fuselage and not epoxied in.
Well the answer is screw it back in! (clockwise), using two nuts on a 10 mm bolt. Will plan on epoxying in, but want to get out tomorrow. Now I did "clean" off some excess epoxy around the top of the screw insert (see rear insert) that was chipping off, thinking now that was what was holding it in, besides the threads. That epoxy cap was also a little proud, that was another reason I decided to remove it. Insert is tight, maybe every time I unscrewed the stab. screw I was rotating the insert out a little more each time because there was no longer an epoxy cap, like on the rear insert, to stop it from rotating out.
Decided to remove insert, clean out hole with 70% isopropanol and a Q-tip, dry out, and then coat upper half of threads on outside of insert with epoxy and screw back in. That way there will not be any epoxy on the fuselage saddle. Had a small amount of old Devcon 2-Ton epoxy, used it because it is water proof in 24 hr. If it does not keep the insert tight will go to SixTen epoxy which needs 7 days to cure before exposure to water.
Well that was wishful thinking, Devcon epoxy did not hold insert. Now when I had to replaced the 3 wing inserts, that got pulled out after a gust of wind picked up the whole kit and threw down the beach 30 feet, I used slightly larger OD blind inserts and they came in a 5 pack so had 2 left over. Used one blind insert to replace the loose open end insert for the front stab. screw and epoxied in with SixTen. Oh, and this time after treating blind insert with muriatic acid for 15 min. then washed under faucet for a min. and then put in hot water for 10 min., then coated outside with baking soda to neutralize any trace muriatic acid, and put back in hot water for another 5 min. If you do not get all the muriatic acid off it will degrade the SixTen epoxy.
The reason I think AFS used open ended inserts is because you can then use the same length screws for all inserts because they pass through the insert, with a blind insert screws sometimes need to be cut to length in order to not bottom out in the blind insert, depending on the thickness of the wing and stab which is different for each wing/stab hole especially on a big wing. But then with open ended inserts epoxying them in is a problem because epoxy can get up inside, so that may be why AFS did not epoxy in the inserts. With the blind inserts I fill the hole with epoxy and then screw in the insert, the blind insert then forces out the excess epoxy as it is screwed in making the epoxy fill all gaps for a super strong bond between the fuselage and insert.
Epoxy will not set a helicoil, will just thread itself out. Previous pigheadedness in previous threads is probably the reason no other responses....
have had same issue with other brand foil and managed to sort it. No six ten involved. Just sayin
So the three inserts for the wing were epoxied in the same way a year ago and are still solid! Here is a pic of the 3 old wing blind end inserts and the new stab blind end insert for those of you who are stubborn, hey I understand. Remember when the world used to be flat, and our solar system rotated around the earth?
And please remember West Systems support knows their epoxies better than anyone, period. They told me over a year ago that SixTen would work for this application and it has perfectly!
Year plus old wing blind end inserts epoxied in with SixTen after many impacts with bay bottom and sea life.
New stab. front blind end insert epoxied in with SixTen.
The reason I did not use SixTen right away is because it takes 7 days to cure for water exposure, but only 48 hr for strength purposes. Then I realized I could put a layer of Gorilla tape over the whole stab. saddle to seal the exposed SixTen epoxy, and cut out holes for the screws, and then I could use it in 2 days.
And for those of you who are not familiar with blind end inserts, here is a picture of one on the left-side next to an open ended insert on the right-side. Note the solid bottom on the blind end insert.
Now this is a picture of a brand new blind end insert, before being sanded and then etched with muriatic acid. The bottom is easy to sand, but in between the threads is not, that is why I use the muriatic acid since it gets everywhere. Just be careful, muriatic acid will give off a visible cloud of acid when bottle is first opened, do not want to breath or get in eyes, so I wear safety glasses and wave my hand around to disperse the initial cloud and any after pouring into a small plastic container, then cover container so no more fumes are released.
And here is the setup I use to treat blind insert with muriatic acid, cover is off. Use two nuts to lock insert to bolt and screw into fuselage, then un-tighten nuts to release bolt from insert.
So I am impatient to get back on the water, good wind right now, and 48 hr cure time means I will lose another day. Thought about warming up the fuselage to speed curing, called West Systems to check, sure enough if you keep at 100-110 degrees F for 6-8 hrs cure time is reduced to 24 hrs!
So am trying a heating pad, will check with infrared thermometer to see temperature.
Heating pad went to 125 degrees within 5 minutes on High, so backed down to Medium setting and is now around 100 degrees on outside, but 115 on inside, so backed down to Warm the lowest setting and now fuselage is 106 degrees while outside of pad is 91 degrees. The pad is folded over the fuselage one time.
Turns out my heating pad has a safety timer, turns off automatically after 3 hr. Resets after being unplugged and plugged back in.
