OOPS- Screws ?????

Bruce · #1 05-25-2009, 06:15 AM

Have the canopy done and ran into a problem. Used a #30 drill bit on ALL
the holes for the canopy so the 1/8 inch plexi bit worked and then took all
to 5/16 after the MC. NOW I ran into the problem. The back canopy has #30 holes on the rollbar and they need to be tapped for #6 screw. You know where this is going. HOLE IS TOO BIG. It did tap for the #6 but the holding power I don't think is there. Don't want to take to #8, because of the MCing that needs to be done.
I am going to put a few screws in and see if it will hold.
What about blue locktite?????
What else can you use instead of locktite????????

Thanks in advance and maybe I will have it figured out by the time I come back and check it.
Sikaflex is out on the rollbar but will use it on the back of the aft canopy.

Thanks,
Boomer

L.Adamson · #2 05-25-2009, 07:13 AM

for starters...........Locktite will haze the canopy. Don't use it!

L.Adamson

FrankK90989 · #3 05-25-2009, 07:15 AM

Ah I have the fix.. use a "rollform tap" #6-32 uses a 1/8 hole a #30 will work fine. roll form taps are well-- "if your not using them your missing the boat"
No chips rolled threads, less broken taps. If you cant find one I will send you one.

Ted RV8 · #4 05-25-2009, 10:29 AM

Do Not Use Locktite around plexi. As stated above it will at minimum graze it. On a stressed piece like a conopy it will crack it.

Don't ask me how I know this, OK I'll tell. It was not on my canopy!!

I did a job on a plexi piece and used locktite on some flat head screws thinking if I tightened the flat head screws to much it would crack the plexi. So I locktited them and barely snugged the screws all was OK. When my customer came in to pick up the job the next day the plexi was cracked around the screw holes. Called my plastic supplier about this and the first question he asked was "did you use Locktite on the screws". This was before I evan told him about the locktite!!

Apparently locktite reacts with the plexi and will crack it every time. Lesson learned and had to by another piece of material and start the job over. At least it wasn't an expensive canopy.

Ted

Bruce · #5 05-25-2009, 06:08 PM

I know about the locktite.
What is the substitute for it.

I have to go to a #8 after talking with a machinist friend.
I will do that on all the ones that don't have clearance issues.

Thanks for all the responses.

Boomer

rv6rick · #6 05-25-2009, 06:15 PM

Respectfully.....I'd have to see this. I've used lots of taps and there's no way I'd put a #6 screw in a hole that was drilled #30. I can see you tweaking the last quarter turn of the screw now

.

If it were me.....I take it apart and weld over the holes.....smooth them out and redrill proper size and tap. Then just paint or powdercoat and put it back together. It's going to take you....what.....10 minutes to take it apart and 10 minutes to weld the holes.

Quote:

Originally Posted by FrankK90989

Ah I have the fix.. use a "rollform tap" #6-32 uses a 1/8 hole a #30 will work fine. roll form taps are well-- "if your not using them your missing the boat"
No chips rolled threads, less broken taps. If you cant find one I will send you one.

rwhittier · #7 05-25-2009, 06:55 PM

I think I found this on Checkoways site, but I used Vibra-Tite VC-3
http://www.threadlockers.com/vc-3.jsp

Its a plastic like compound you put on the threads and then let them dry BEFORE you put the screw in.

It was hard to find and I can't remember where I bought it. I did a web search for it and only one plane popped up quickly http://stores.kaizen-ms.com/Categories.bok Look around, I am sure you can find it - probably cheaper. Good luck.

Quote:

Originally Posted by Bruce

I know about the locktite.
What is the substitute for it.

FrankK90989 · #8 05-25-2009, 09:10 PM

Its simple, rolled not cut just like our aircraft hardware is made. Again the proper size for a #6 rollform tap is a 1/8" drill. (#30 will work fine)There are no flutes on a roll form tap. search the web for more info.......
http://www.advancedrapidmachining.co...ill-sizes.html
http://www.precisiontwistdrill.com/t..._prod_taps.asp

Quote:

Originally Posted by rv6rick

Respectfully.....I'd have to see this. I've used lots of taps and there's no way I'd put a #6 screw in a hole that was drilled #30. I can see you tweaking the last quarter turn of the screw now

.

If it were me.....I take it apart and weld over the holes.....smooth them out and redrill proper size and tap. Then just paint or powdercoat and put it back together. It's going to take you....what.....10 minutes to take it apart and 10 minutes to weld the holes.