mburch

mburch

Well Known Member
Patron
Hi all,

I presently have my slider canopy split and the slider portion is trimmed to fit the frame. I'm ready to start drilling the plexi to the frame, but I've heard various bits of conflicting advice on how to proceed. On the Orendorff tapes, he appears to just blast right through the plexi and steel both with a regular twist drill, ignoring the issue of special plexi drills (and their poor ability to go through steel). I emailed Van's and was told:

You can drill through the plexi with the plastic drill far enough that it starts a hole in the frame, then remove the plexi and finish the hole with a regular drill.
Click to expand...
If I read that right, I would be removing the plexi from the frame after every hole, which doesn't sound like much fun.

A third way I've been pondering would involve using the masking tape method to find the centerlines of the various tubes, then marking and drilling the holes in the canopy frame without the plexi in the picture at all. Then the plexi would be clamped to the frame and the plexi holes would be drilled with a plexi bit, lined up by eyeballing the existing holes in the frame through the glass.

Thoughts/ideas/opinions?

thanks,
mcb
 
NO NO!

The key is to get the plexi in a hot or very warm enviornment. If you drill the canopy in these conditions, plexi bits are not really required. Heat the canopy from the bottom if needed. Do not drill separate, it will never match up!
 
drilling canopy

well, i haven't started that yet, so take my comments with the appropriate measure of salt.....

If I read that right, I would be removing the plexi from the frame after every hole, which doesn't sound like much fun.
Click to expand...

couldn't you just drill them all to the "start hole in frame" point and then remove the plexi once and drill all the holes in the frame?

A third way I've been pondering would involve using the masking tape method to find the centerlines of the various tubes, then marking and drilling the holes in the canopy frame without the plexi in the picture at all. Then the plexi would be clamped to the frame and the plexi holes would be drilled with a plexi bit, lined up by eyeballing the existing holes in the frame through the glass.
Click to expand...

i'd be reluctant to do that on account of diffraction (refraction, whatever.) i suppose it would be no big deal, because don't you eventually drill the plexi holes slightly oversize to allow for expansion/contraction? but i'd still be nervous.

i think when i get there (hopefully in a coupla weeks) that i'll use the orndorff method -- after all, i just bought a bunch of those drill bits from eric :)
 
drilling plexi

I just did mine and it went smoothly even though my canopy was cold!!! The problem with drilling plexi is not the first hole, it is enlarging the hole. I drilled all my through holes with the regular steel bits and clecoed each hole as I went. On any holes that I enlarged I used a bit where I had ground off the cutting edge. The danger is that when a larger metal bit goes through a small hole in plexi the cutting tips grab the plexi and push it apart causing splitting. The real plexi bits shave their way through. I found the canopy much easier than all the worrying I did before I actually began working on it!
 
Warm plexi is a good idea, something above 70 is o.k. You can, however, use a regular 135 split point that is the rivet size for the first hole simultaneously through both plexi and frame. Clamp, clamp, clamp, tape, tape, tape,..., use shims as required as you proceed; the holes will never line up around the curves if you introduce shims or attempt to tighten or loosen the fit after drilling. The drill caution has to do with opening an already existing hole, e.g., from the rivet size to whatever is called out as a clearance hole in the plexi (5/32?). It is here that you MUST use a plexi drill. They are not aggressive. A split point will snag the edge of an almost-the-same-size hole and pull itself uncontrollably into the hole. That is how cracks are started.

John Siebold
Boise, ID
 
I did mine with a regular bit with the canopy clamped to the frame. Use a high speed air drill and let the bit melt its way through the plex before you push harder to drill through the frame. Once you start the hole in the plex you are commited so keep the drill going until you have drilled completely through the plex and framework. This is VERY important, if you stop you WILL probably break the plex. I just ground a taper in a regular drill to enlarge the holes in the plex. I have my canopy finished without a crack so I guess I did it right. Don
 
Follow up

Thanks for all the tips guys - I ended up drilling the initial holes through the plexi and frame together with a regular #40 bit and everything was fine.

cheers,
mcb
 
Words....

Original quote:-

Quote:
You can drill through the plexi with the plastic drill far enough that it starts a hole in the frame, then remove the plexi and finish the hole with a regular drill.

I wonder if this should have said...

Quote:
You can drill through the plexi with the plastic drill far enough that it starts a hole in the frame, then remove the plexi drill and finish the hole with a regular drill.

This is the way I did it.... one word added can make quite a difference... :)

gil in Tucson
 
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