Sinking carriage bolts into plexi

[jeffhlewis]

I've got carriage bolts that hold my plexi in place.  I noticed after doing all my plexi drill work that the little square shapes under the bolt heads keep the bolts from fitting flush.  The holes for my bolts are just drilled to the bolt size.  The picture below shows what i'm talking about.



Anybody know of an easy way to expand these holes to accomodate for the squares?  Can I melt the plexi?  Can I heat up the carriage bolt with a soldering iron and sink the bolt into the plexi (sounds crazy i know)?

[BobtheAddict]

The simplelest thing I can think of is to expand the hole you have already drilled in the plexi to match the carriage bolt. I wouldn't recommend heating the plastic to mold around the bolt. What happens when you want to remove the plexi later on?

Lowe's or Home Depot might have an alternative bolt you can use without the square piece.

Just my 1/2 a cent.

[TAG]

Lowe's or Home Depot might have an alternative bolt you can use without the square piece.

Lowe's does in fact carry "carriage screws" without the square section under the head.  You'll find them in the green drawers in the fastener aisle.

[jeffhlewis]

Problem solved...looked around for square-less carriage bolts but no luck.  I did however find a "bastard file" for $5 that worked wonders.  Just a quick 30 second file on each bolt hole to expand it a bit and the bolts sank right in.  I did have to take the plexi off again to windex the CPO but no biggie.  Now i'm ready to roll.

thanks for the help guys!

here's a pic of what I used in case anyone is curious:

[Franco B]

FYI, that is a round or 'rat tail' file. Bastard is the roughness classification while lies between a rough file and a second cut file.

[Paulson]

 I thought using a square file would be better as the bolt won't spin as
 it is tightened...

 

 Just a thought.

[jeffhlewis]

The bolts don't spin - the round file was small enough that I could file out a square shape on all 4 sides of the hole.

[erictrumpet]

Bastard is the roughness classification

That's one of those weird word usage things that just seems wrong. Like the proper term for a female breeding dog. Ever hang out with dog breeders? When talking shop, they drop the B-bomb every two minutes and it's always a little startling.

Eric.

[scotthh]

I find that the push buttons hold the plexi securely and there's no need for extra bolts.