Acylic Windscreen Fix
 

I have an acrylic windscreen that has a small break in it. Is there a was to fuse this together. If not, what is a decent glue or epoxy to use.... superglue?

Superglue.

If the crack will go back together "completely", then press it back in place, and run a bead of "thin" superglue down both sides of the crack.

Do NOT put glue on both "sides" and then press it together. Superglue uses capillary action, and will "go into" the crack on its own.

There are specific acrylic "glues" that may work. I have an acrylic fish tank and I belong to a message board that has tank builders as members. I will post your question there and see what they recomend.

You may be able to "solvent" glue it. Most plastics can be glued through the application of the proper solvent which will allow the plastic to melt back together and bond. You need to see a plastics place or check with a national place like www.piedmontplastics.com for info on the proper solvent. If done correctly there is little difference in the strength of the bond and the product.

The "glue" you want to use is a solvent cement. Solvent cements essentially "weld" plastic parts together by dissolving the surfaces where the glue is applied long enough for you to join the parts. Once the solvent evaporates, the plastic solidifies, and the parts become one. If what you're repairing is Plexiglas (or any styrene based plastic), the cement you want to use is called Comstik Cement for plexiglas. You can contact TACC International, Comstik Adhesives Division, Trenton NJ. 08619. (609) 584-1623. This is a very thin liquid that works by capillary action. If you are fixing a crack in a windsheild, the first thing you have to do is drill a small hole at the base of the crack. This is called a "Crack Check Hole". It's to keep the crack from spreading. Then you use the solvent cement as per the instructions on the can. When you order the cement, order the applicator bottle too, you'll need it. Unless you're going to use it a lot, order the small can. This stuff is so volitale (evaporates quickly, not flammable), that once you break the original seal, the contents will evaporate. Takes a while (1 year for my pint), but it will. Order a tube of their thickened cement. It's the solvent cement with plastic dissolved in it. You can use this as a filler to fill the crack check hole. I used this years ago on my Tahiti windshield. I beat the hell out of that boat for five years, and the joint never seperated. I've been using it ever since.

Paul:fish:

Thanx all,

It's not big enough to replace the windscreen section, but large enough to bug me...

It is called methylene chloride

It is called methylene chloride

You're right. It is methylene chloride. But it will be easier for him to call the phone number, and order a can of Comstik, then trying to figure out where he's going to get methylene chloride. Unless he has a source for this kind of stuff.

Paul

CAREFUL

if the windscreen is Lexan, then MEK (or plexiglass solvent glue) can/will cause cracking and crazing. Might not show up on day1, but can come back to haunt later.

I'll call Baja

Methylene chloride, can safely be used on Lexan. I did some research, and everything I found said it was OK. Don't use MEK! That's Methel Ethel Ketone. Not the same thing. If you're not sure, call TACC International. They'll tell you if it can be used on Lexan.

Good catch.
We used to use MEK on just about everything. Used it as a plexi solvent glue, used it to clean brushes, used it to clean everything. I expect we will end up with some nasty cancer one day.

MEK is nasty stuff! I used to use it to degrease parts prior to doing accelerated aging tests on deep drawn aluminum components (As per UL spec).

Shooter my windsheild cracked so i took it of an took it to a place called plastic menders. they sad they could fix good as new, well a long story short is dont waste your money. unless it is not visible.

I have done this repair. The boys are right. Methylene Cloride!!! A squeeze bottle applicator with a small hyperdermic needle is used to apply along the break. If done right it will look O.K. The real trick is to not use too much M.C. as it will etch the plexi. M.C. fuses the pieces together and is a strong repair. I happen to work next door to Commercial Plastics in Queens NY and they are or were afilliated with comstic. They are called Comco now and are owned by G.E. Plastics. They actually make plexiglas there in autoclave's. Every other night a tractor trailer tanker of plastic pellets unloads through a steel flex hose. What noise that makes ! Also the smell from the melted plexi gives me a migrain ! Maybe a little too much info though. Always HAVE FUN<BBB

Also have used MEK in a metal shop I worked in 12 years ago. Basically it gave you a rush. After not using it for a week I developed severe withdrawal symptoms, such as depression, and malaise (feeling out of it) which took me about a month to realize. This stuff is bad news. Also used Methylene Cloride to strip paint off of parts. On a hot summer day it would evaporate almost as fast as I poured it out of a 55 gallon drum. Even with a rubber hood and gloves and a supplied air respirator. I felt a rush of cold then hot when entering or leaving the area. I sometimes worry about the potential of future health problems. I guess when your 18 19 and 20 years you don't think of these things. BBB :(