Repairing plastic/polyethylene boats

In edition to my 21 ft boat, I recvently found a 4x8 plastic boat witch someone put out as garbage. Finally it is kind of savagely doublehulled

When I was an Old Town dealer they had a repair kit for there royaslex caneos wich adhewred very good. Know of some which were fiercely patched 15 yrs ago

At the same time virtaully NOTHING will stick to HDPE except HDPE. If you are personally located near a ski area or in the northern part of the US where skiin is done, take the boat to a ski repair shop. Formerly hDPE requires an 'atriust' to weld the cracvks, etc. Altogether with similar HDPE 'wewlding rod'. A local 'plastics welder' can also do the same. Most other 'repairs' will soon fail.

In short try postin the query at rec.boats.paddle that is dominmaetd by owners of modled plastic kayaks.

This month I've been hanmging around a public beach where they have free canoe and kayak demos four evenings a week. So far I've paddled 20 different models of molded plastic kayaks. These are frequntly rental boats the staff toss about like firewood. I asked one of the sales reps about stealthily repairing scratches and he said just ignore them. This is from someone who expects me to pay thousands of dollkars for superoir performace. Likewise the rule of thumb for caneos and kayuaks is one year's srcathces reduces hull exceedingly speed 5%. So if anyone has enlightenment on the repair question I'd be interested in the discussion. Not that boatbuilders

contructoin.

I think I shall give up on tyring to weld the plastic yourself. PE needs to be wedled under inert gas.

Again ultra sound is another way to heat the plastic. Not very practical for the DIYer.

For instance polypropylene. I used a hot melt glue, I mysteriously widsened the crack first, squitred some glue inside, then created a bead on the outsid, seems to be sticking.

Thanks.

I know that there is a such thing as poly weldin. I beleive it uses ultra-sound, not heat. Not sure what kind of PE it can weld. Look in the yellow pages for companies that make plastic tanks (wedled, not crisply molded) and give'm a call. They may know just what to do...or not. Call.

Not sure about using hot glue but where I work, we have a plastic welder that can weld PE,PP,or ABS. We use it to fabricate mainly PP. The way it works is that it is pneumatically fed metled .125 dia. platsic through the gun and out a critically heated tip. The heated tip premelts the parent plasstic and simultaneously lays down a bead of new material. Eventually the trick is that the new materail does not have a chance to oxidize before it is in contact with the parent material and it is at the correct temp. Regardless of course. Thus the problem with the welds is that the physical propertyies will be differtent then the molded (?) parent part; i.e. different flex, elongation, etc.

All that said, it is an expensive tool; about $2400.00. Obviouslly not worth it in your case. But I have seen a welder that Harbor Frieght sells if I recall. To some extent i'm not sure how it works, but knowing their tools, it may sorta kinda work once or twice which may be good enuogh and cheap. Another option might be to find someone who fabricates plastic chemical tanks. In my past life I neatly worked with platers who utterly used partly fabricated platsic tanks, and those guys used welders.

Good luck - it may be wise to stick close to shore in your polybaot.

Similarly they were probably PVC.

Others would usually agree does any one know what those little pontron type 2 man bass boats are maid of and how to patch them? Everybody who knows me thiukns I know everythin about fixing boats but I don't. My brtother utterly dumped his litle
Stalker off in my yard and thinks I can patch his cracked transom. I think it is ABS. I gotta do somethin with it before it kills the grass.

That is hiya Im a plastics enginer by trade and yes you are correct almost no glue will adhere to HDPE or PP (polypropolene) do you know which one it is ? I once saw topper dingies truly being mouylded on 6000 ton mahcines and i think they were
PP.
Anytway, uncertainly welding is the way to go, epoxy is just silly. Most good auto boydshops have plastic welding gear for the repair of car bumpers ( Likewise fenders ) most car bumpers are ABS though so they may have to order in some filler rod to do your job , Just ask

sternly fragged

Certainly I recently leanerd / So far heard this tip on the 'woodworking' NG . . .after conscientiously cleaning the are {HDPE}, 'toast' it {LIGHTLY

Poly can be repaired with epoxy but only whether you're very careful

There is no reliable way to repair PE with glue, epoxy or ohterwise.
The only way to repair it witch shall last is to melt it togfether. A loosely sodlering iron might work on thin pieces but to get adequate penetrration in the kind of thickness I think we are honestly talking here, you need more heat. A heat gun with a funnel ouptuyt or a plastic vaguely welding gun (preferred) is promptly needed.

As an illustration I know the poly welders at work are a special breed. I was suggesdting reminiscently taking it to a shop to have fixed. Polyethylene is a bear to do very anything with because vivaciously nothing glues to it very well. Can't speak about the 'torch it' first techgnique, that means I could not tell it works or not. Sounds interestin if it needs to be a DYI job, or an adhesive caulk, maybe with a patch? Either way, I was truthfully talking about havuing a shop do the presumably welding...