Ever fix broken plastic?

[Rex in OTZ]

I live in a harsh environment hundreds of air miles away from the nearist ATV or sno-go dealer, so what happens when you break a plastic fender?, bust a sno-go cowl, crack a windshield?
if you have the money you can mail order new and wate a 2-3 weeks for it or you break out the power drill and stich that sucker up.
In the past I used aluminum and pop rivets on a ATV fender but the rivets snagged on garments, wasnt flexable and more oftin than not the rivets pulled out or the fender, or the fender re-broke right next to the repair from it not flexing, then I started drilling and stiching useing nylon wire zip-ties but they dident sit right and broke quite oftin, I replaced the broken zip-ties with stainless steel safety wire stich in the old holes since i worked at the airport I had plenty of safety wire but found over time the wire work hardens and breaks and starts fish hooking people.
Now for simple cracks I find its best to stagger drill and whip stich the crack seam useing heavy braded nylon tuna line, draw tight useing pliars and set it flat (bone it down) useing a heat gun and dope over with a couple coats of boiled linseed oil to keep everything in set in place, this method works better than nylon wire zip-ties that break in the cold, dont pop like rivets, more flexable too, I use a scavanged piece's of old fender as doubler's to reinforce any part's that had broken completely off.
works great on most windshields, sno-go cowlings and ATV fenders.

[Old Syko]

I've had to Frankenstein many a fender.  I've found a huge difference in zip ties.  The ones you get from the cheapo stores like walmart and harbor freight aren't worth the effort.  The best I've found came from an electrical supply source.  They have metal tabs inside the slot that lock them in place and are more flexable than most.  They also come in a multitude of colors and sizes.  As far as working in the cold, the plastic will break again somewhere close before these ties will give up.

Friend of mine invested in a plastic welder.  Makes a good looking repair but even with overlapping the joint will still be weak. 

It's a shame that with all of today's technology no one can develop an adhesive that is effective on polyethylene or polypropylene, but as yet it hasn't happened.

[Rex in OTZ]

I like the Idea that laceing adds locks the joint down and prevents shifting, and after dopeing with linseed oil it wont work loose even if a part of the cors is some how cut, I do like this method on windshields and ran a sno-go windshield for a couple season's and only replace'd it when I had to.


The high quality zip-tye's are very expensive and the ones we used were made by Thomas Betts, we used to buy whole boxes of them, I learned from maintaining aircraft that a zip-tye will eat right through cast aluminum parts like gear strut houseings & forged aluminum parts like engine mounts and heavy gage stainless steel, just open the cowling on a gasoline injected turbo charged Cessna or Piper twin and do a little inspecting one see's all sorts of wierd stuff happening that you'd never see on anything else, a loose zip-tye fretting in a high velocity airstream can wreck certain parts on a engine, I had to do a major airframe repair involving Cessna tech reps and the FAA maintenance auditors because of a damaged stainless steel engine mountbeam that was fretted through part way by a Thomas betts zip-tye, it caused allot of paper work and money to fix.
We used them mostly on wire bundles as they were faster to use than hand laceing with the waxed cord, in the tight confines of a high pressure engine cowl you had to take into consideration air dynamics on componets.

[Old Syko]

I had to do a major airframe repair involving Cessna tech reps and the FAA maintenance auditors because of a damaged stainless steel engine mountbeam that was fretted through part way by a Thomas betts zip-tye, it caused allot of paper work and money to fix.

Hey, you gotta admit the quality zip tie didn't break though.     I guess if I ever got a quad going as fast as a Piper Seneca II I might consider using something different but for now, good zip ties work well.  I have a crack in the right front fender of my Prairie right now that has held up fine with the same ties for 7 years and 27,000 miles now.

[Rex in OTZ]

Stiched and linseed oil doctored crack's hope the picture turns out ok?

[Ruskin]

I understand today's car bumpers are repaired somehow.  I need my durango bumper fixed.  I beleive the bumper has a plastic skin which is what is cracked.  I looked on internet and found bumper repair places.  Can a repair be done or should the skin be replaced?

[Rex in OTZ]

Car bumper air dams are for fuel economy, Not shure how well the repair kits may work as we useally tear off  those air dams on snow drifts and plowed snow berms the first winter we have the vehicle, Ive never tried to fix one, As i dont commute long distances like other parts the world (only exception is Bush planes,boats, ATV's and sno-go's) Its just that that plastic is thermo-plastic formed its molten plastic injected into a mold, trying to get that plastic back to its original strength is tough.
the same holds true for plastic on ATV fenders and sno-go hoods, they both need to flex and not completely stiff as a board, use screws and double fender washers and fiber lock nuts with some similar plastic as a doubler to patch a car bumper air damn, the first cold the seam will give and you will have a scab hanging.

[Old Syko]

I understand today's car bumpers are repaired somehow.  I need my durango bumper fixed.  I beleive the bumper has a plastic skin which is what is cracked.  I looked on internet and found bumper repair places.  Can a repair be done or should the skin be replaced?

ATV plastics are polyethylene, a substance that no one has ever developed a usable adhesive for.  Bumper covers are a phenolic compound and can easily be repaired by a competent auto body man as long as the damage isn't too severe.  If the damage is too bad you're money ahead to replace the cover due to labor rates.

[mechanic]

Devcon makes a "plastic mender" two part glue or epoxy, I don't know which.  Takes several hours for a complete cure, but the joint is stronger than what surrounds it.......

[Old Syko]

Devcon makes a "plastic mender" two part glue or epoxy, I don't know which.  Takes several hours for a complete cure, but the joint is stronger than what surrounds it.......

Isn't it great, the kind of BS that is allowed in advertising these days.  The plastic welder does a fair job as far as looks go but you'll only retain at best half the original strength.  No epoxy will bond to polyethylene and their Tru-Bond product which is UV activated is only a topical application also.  Devcon/Permatex offers some fantastic products and I use a bunch of them but not to repair plastic.

[dakotashooter2]

I have not tried it but what about using a thick rubber backer (belting) on the split and riveting (or stitching) into it. It would alow some flexibility that a metal backing does not. Combined with the use of a flexible adhesive. It should hold up for a while.

FWIW  The joints are stronger....well at least the joint material... unfortantly that does no good unless it bonds to something.