I Need Some Plastic Boat Help

[gilb2000]

I have a 7 to 8 year old basshunter BH2 10ft 2 man plastic boat. it is a 2 piece hull design that use to have a black strip holding the top and bottom halves together with a few small screws.. eventually that strip went haywire and i had to remove it and the boat began to have separation. Well my bright idea was to drill holes every 3 to 4 inches and bolt and silicone the 2 halves together.. the boats held together fine and floats and all but the plastic has puckered between the bolts making gaps.. So in a effort to fix it right i have removed all the bolts and silicone, have the hull separated and the foam that was in the pontoons out to try to dry.. i was gonna try to take a plumbing torch and very gently heat the plastic to try to get some of the puckering on the seams out and then Epoxy the 2 halves back together followed by fiberglassing over the seam to replace the original black strip.. Would this be a logical fix and is there one product better than another or one that will work and one that wont?

 

[a70eliminator]

Re: I Need Some Plastic Boat Help

Seems like the first attempt was a good one except you needed to pin the front, then the rear in the center, then the center of the each side and work outward evenly, if you just start at one point and go that's where you get the puckering at the end. You should try once more and no silicone, use something like 3M 4200 and put a bead around after your all happy with it.
Large pop rivits work too maybe you could reuse some of the holes and fill the others with 4200. Your next plan of attack sounds good too just rough up the plastic with some 36grit to give it some tooth.

 

[gilb2000]

Re: I Need Some Plastic Boat Help

yeah i gotcha .. well the puckering was not from misalignment but just the plastic raising up in between bolts making almost a football shape between bolts.. that make sense ... looks like this () but horizontal

 

[a70eliminator]

Re: I Need Some Plastic Boat Help

Yea thats makes sense, maybe use some nyloc nuts that way you won't have to crank them so tight, just bring the halves up to almost touching then squirt some good adhesive sealant between and bring it up just till the halves just start to push out the glue and stop there don't overtighten.

 

[EsoxRanger]

Re: I Need Some Plastic Boat Help

I would use Sikaflex 292 as the adhesive/sealant. It would take a healthy ball of c-4 to break it's bond.

 

[HappierWet]

Re: I Need Some Plastic Boat Help

I would think the Epoxy is a bad idea, the curing temp would be bad for the plastic......some kind of adhesive sealant seems the way to go with lots of clamping while it's curing

 

[fishrdan]

Re: I Need Some Plastic Boat Help

Yeah, silicone wasn't a good choice for the plastic boat as it will just scrape off, been there, done that. Test 3m 4200, 5200 (or the sikaflex?) on a part of the boat to see how it sticks to the plastic, I'm pretty sure 5200 will.

To get the bows out, heat up the section (sloooowly) with a heat gun and then clamp a piece of wood or metal top-bottom until it cools. It's going to be hard as you want to heat the lip, and only the lip and you will need to work in small sections at a time. I've reformed that type of plastic before and it's do-able, just go slow.

 

[ondarvr]

Re: I Need Some Plastic Boat Help

Neither epoxy nor polyester will bond to that plastic and a torch will make a mess. Some adhesives will sort of bond to it, but not well, more screws, rivets, or bolts (your choice) and a good sealant will most likely be your best bet. Just put the fasteners close enough together so there's no way for it to bulge between them.

 

[Iandayen]

Re: I Need Some Plastic Boat Help

Sickaflex is amazing stuff, it will work great for your purposes.

When I was a diesel mechanic we used that stuff all the time. I still have pants that are 5-8 years old and been through many washings that still have that crap all over them.

 

[tashasdaddy]

Re: I Need Some Plastic Boat Help

those boats are built of the same plastic as the lids on coffee cans. there is a special dow-corning, adhesive for them. i patched a hole several years ago in one. they told me to use that adhesive, cut the coffee can lid, to fit the patch. heat a little so it was plyable and just set it into the adhesive.

sorry, i do not have the tube anymore, or remember the name # of the adhesive.