Canopy cracked

[tireguy]

Well after 15 years in service my RV-8 canopy has developed a small crack by my canopy latch. It?s sticking up out of the skirt only 1?.
Still looks like a middle finger to me. I?ve read several posts on the subject, but, I can?t find and information on the best SIZE drill bit to use for stop drilling.
I?d like to have a small as possible hole but want a large enough radius to put the ?shut up? on my crack.
Any help would be great.

[rockwoodrv9]

Check this thread out on repair possibilities. Looks like Scotts repair is doing well.
http://www.vansairforce.com/communit...d.php?t=156810

[tireguy]

I read that post already, that?s a big crack! Mine is small. I?d like to find the most effective size drill size, that will do the job in the smallest diameter possible.

[AlexPeterson]

You probably know this, but be sure whatever drill you use is either made specifically for acrylic or modified appropriately.

[tireguy]

Yes, used a plexiglass drill bit when I built the airplane. But the smallest size I can find is a huge 1/8. I can modify any bit by (drilling in concrete to dull) or grinding a 60* rake on the bit..

I still don’t know what is the optimal size to use. And, instead or drilling, should I melt a hole instead?
I’m leaving from NH to Seabring tomorrow, or Thursday, and need to do something before I leave..

[rmarshall234]

I'm not sure there is an optimal size. I would think the larger the hole the more effective however. But, also more unattractive. In A&P school they told use to use a number 40 or a number 30 drill. Want to make sure you drill far enough out to include the _entire_ stress riser though. (called the "point of inclusion" if I'm remembering correctly??) Otherwise the crack will develop on the other side and continue onwards. Good luck.

[Richard@Langair]

Dont melt a hole, When Plexi gets too hot it also becomes very brittle. The edges of that hole will be extremely brittle and be very prone to cracking even more.

[Ironflight]

Originally Posted by tireguy

Yes, used a plexiglass drill bit when I built the airplane. But the smallest size I can find is a huge 1/8. I can modify any bit by (drilling in concrete to dull) or grinding a 60* rake on the bit..

I still don?t know what is the optimal size to use. And, instead or drilling, should I melt a hole instead?
I?m leaving from NH to Seabring tomorrow, or Thursday, and need to do something before I leave..

I checked a few references and didn?t find a recommended size either. If it were me, I?d use a #30 just to make sure I gave the stress sufficient area to spread out, then put a daub of clear silicone in the hole, let it cure, and head to Sebring.

[RV7 To Go]

I would use the 1/8" plexiglass bit and then use Weldon 3 plexiglass adhesive on the crack. It has the consistency of water and will wick into the crack fusing the plexiglass together as it dries. You could fill the hole with plexiglass shavings and then fuse it all together with the Weldon. If you do use silicon don't use the acidic type or you risk more problems.
Al

[bret]

It was nerve racking drilling that 1 hole in the slider. I used a 40, and be sure to not let it pull the bit through the back side as it comes through.