Fiberglass questions

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
RickMc
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Fiberglass questions

Postby RickMc » Mon Dec 19, 2016 4:48 pm

Hello, I'm getting ready for my Florida trip this year and i want to redo my hull. It is in need of some minor transom work and a little paint. Its really light ,maybe 3/16,previously had polly but the holes have been covered over. There is a coating of some sort of quick slick that the previous owner said was his own formula. Whats the best way to remove that ? Just sand it? I was thinking about another layer of glass over the bottom and the transom because its so thin and it has a lot of holes . What is stronger mat, mesh, carbon fiber, kevlar? I should be thinking about polly with the rocks in the river here but i love how light the boat is and how it runs under my 0320 . Is this a project for the home garage or should i be seeking profesional help? Thanks for your input Rick
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mojoe
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Re: Fiberglass questions

Postby mojoe » Mon Dec 19, 2016 9:00 pm

I have never glassed the outside of a hull. The inside and stringers is easy and I doubt the outside is much different. Kevlar is bullet proof.. and expensive. You asked a lot of questions ther. Are you looking for the best thing, or the best reasonable thing?

To me, the biggest question is: What do the other local boats run? They know what you need. A lot of lessons have already been learned.
Airboating is like marriage: There are unlimited ways a person can be right, and somehow still be wrong at the same time!!

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Re: Fiberglass questions

Postby Gary S » Tue Dec 20, 2016 5:58 am

If the bottom coating is wearing away, grind what is remaining and redcoat. I think Fasco epoxies ships. Use the steal flex 2000. As far as reglassing the bottom, you are opening a can of worms I doubt you want to open. First all gelcoat has to *** off so the new glass will stick properly. As far as material, your woven weather its Kevlar or glass is uses along with the mat. I have never used carbon fiber so I can't comment on it, but I believe it is used with epoxy resin. After you glass the bottom you have to get it smooth and flat. A lot of grinding and filling. Hope this helps.

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Deano
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Re: Fiberglass questions

Postby Deano » Tue Dec 20, 2016 12:13 pm

RickMc wrote:Hello, I'm getting ready for my Florida trip this year and i want to redo my hull. It is in need of some minor transom work and a little paint. How do define minor? Can you post pics?

Its really light ,maybe 3/16,previously had polly but the holes have been covered over. There is a coating of some sort of quick slick that the previous owner said was his own formula. If the previous owner was Brian, then QuickSlick is what's on there and I would only use that to overcoat it, if need be. Otherwise, as Gary suggested, Steel Flex is a sound choice and Fasco can advise you there.

Whats the best way to remove that ? Just sand it? If you are asking about the whole bottom, a belt sander is far and away the best option. You do not want to use a side grinder or a drill with a sanding disk because you will make a bunch of divots that then will need to be filled. That would only make it thinner, and make for (a lot) more work .

I was thinking about another layer of glass over the bottom and the transom because its so thin and it has a lot of holes . I think you under estimate the amount of time and grief involved in doing this. To do this would require removing everything down to bare glass. I would not say that you can't do it, but there is a learning curve involved. Starting out thin and then grinding down to good glass without removing any, can be an art unto itself. Lacking prerequisite prep work, workable temperatures, etc. you could end up worse off than you started.

What is stronger mat, mesh, carbon fiber, kevlar? This all depends on the 'system' (ie. resin/reinforcement) that is used. Understand that different resins are used for different attributes and require specific applicable reinforcement to attain those ends.

I should be thinking about polly with the rocks in the river here but i love how light the boat is and how it runs under my 0320 . You may have answered all your own questions right there. Keep in mind that polymer is neutrally buoyant so that you aren't adding weight while in the water (except for fasteners). Do you need to run dry? If not, the difference is more negligible than may realize.

Is this a project for the home garage or should i be seeking profesional help? You can do whatever patchwork, repair and reinforcement you need to with a little coaching. I could not in good conscience and don't recommend that you attempt to re-glass your entire hull to make it stronger. As far as professional help goes, in my experience it would generally be more cost and time effective to replace the hull than pay somebody to restore it.

Thanks for your input Rick

With that all having been said, http://www.uscomposites.com/ is a good resource even if only to identify what is available and develop a list of things to research to broaden your knowledge. My only intent here was to help you avoid unknowingly shooting yourself in the foot. We both know you can do anything you put your mind to. :)
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
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terrible ted
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Re: Fiberglass questions

Postby terrible ted » Tue Dec 20, 2016 1:01 pm

I say redo gel coat and slickem coating . Poly is your alternative if you think the bottoms to thin. Will add weight.

RickMc
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Re: Fiberglass questions

Postby RickMc » Tue Dec 20, 2016 3:55 pm

Thanks for the replies. I was worried about getting in over my head with my over thought plan . I often do that. The slick stuff on the bottom is still mostly there except at the rear where it drags on the rocky bottom when drifting and some gouges from taller rocks when under way. A few of the gouges are fuzzy where it got to the glass. As far as asking other airboaters I'm the only one i've seen running. There are some tunnel hulls , canoes and kayaks. If I decide to re-coat with some steelflex will that fill in some of the gouges ? Can I go over whats there? If I go polly is the added weight going to kill performance? What type of business would sell the polymer? No local airboat shops up here. What thickness?
Thanks again Rick
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terrible ted
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Re: Fiberglass questions

Postby terrible ted » Tue Dec 20, 2016 7:23 pm

Poly Is Usually A type of UHMW "Ultra High Molecular weight polyethylene". If you have rocks it may be a good thing. I hit an old dock post and put a round crack it the hull but with the poly it still floated and ran fine the rest of the night. it come in sheets 1/4 ,5/16 ,3/8 ,1/2. I ran 1/4 on my cotton mouth. You can look up the weight and try running with that weight added into the boat. Some math is involved.

RickMc
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Re: Fiberglass questions

Postby RickMc » Tue Dec 20, 2016 7:36 pm

Deano ,thanks for your time on this,in your reply you mention that the polymer is neutrally buoyant except for fasteners. So as far as just floating its only a + or -10 pounds of bolts penalty. Am I thinking that right ? i'm going to require most of a 10 x 5 foot sheet . How much does pushing that extra weight around effect performance in the water ? is there much of a parasitic drag increase ?
My boat barely runs dry now I can crawl on and off the shore but thats about it. Is the polymer more or less slippery than what i have now?
Thanks Rick
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Deano
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Re: Fiberglass questions

Postby Deano » Tue Dec 20, 2016 11:41 pm

RickMc wrote:Deano ,thanks for your time on this,in your reply you mention that the polymer is neutrally buoyant except for fasteners. So as far as just floating its only a + or -10 pounds of bolts penalty. Am I thinking that right ? That is more or less correct. I imagine they all may vary some, but my old notes said 1/4" was 1.17 lbs per sq/ft and 94 percent buoyant. So a 5x10 would be about 58 dry, but only about 4 submerged. Your guess is as good as mine about fasteners.

How much does pushing that extra weight around effect performance in the water ? is there much of a parasitic drag increase ? My boat barely runs dry now I can crawl on and off the shore but thats about it. Is the polymer more or less slippery than what i have now? We have a 15' Rivermaster w/ a 472 DD and 3/8" polymer and it will get in and out of the water just fine. I isn't a mountain goat by any stretch of the imagination, but the point is that it is well over twice as heavy as yours and I surely am not producing anywhere near twice the hp you are. It is slicker than a glass bottom for sure. May take a little more to get on top in deep water (maybe not), but once on top it's much like it isn't there. The little boat has an O290 on it and it gets on and off the beach with 5/16" poly on it.

Thanks Rick
I believe those numbers to be good but would still encourage you to exercise due diligence. In addition to Airboat specific dealers, other places to check would be http://www.tse-industries.com and http://polymersystemsllc.com/airboat-polymer/ and Horn Plastics http://www.superslide.com/.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan

terrible ted
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Re: Fiberglass questions

Postby terrible ted » Wed Dec 21, 2016 8:02 am

Any plastic dealer should have or be able to get it. I suggest black not the white. Its used for more than boats, It used for sliding ,wear surfaces simple bearings.


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