Poly Install.........Screws,Rivets, or Bolts?

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
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whiteriverrambo
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Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

POLY INSTALL.........Screws,Rivets, or Bolts?



Ok, so I kind of feel like this is a stupid question, but for the life of me I cain't find a good "authority" thread, video, manufacturer,
article, or other that says "the right way" to install poly.

- I know screws are for fiberglass boats only, so that's out.......

- Rivets appear to be used in a wide variety of boats, but seem slightly complex....
* As I start to get into this Rivets are the most complex of fasteners, but look the best when done properly as well as have better
head sizes. They not only must have the right size hole, countersink, be the right hardness, and requires pneumatic tool, but also
requires a good technique. could be difficult to do correctly 400 times.

- Bolts should be simple, although poly and simple shouldn't be in the same sentence....
* These could be as difficult as you want to make it I guess. would you drill a hole to bolt size through the hull skin only, through
the T-bar, and back with a nyloc nut? Or would you tap each hole? Or both?

Other questions=
* How far apart should each fastener be on 3/8 UHMW?
* Where would you buy fasteners?
* 5200 or another adhesive?
* How much adhesive?
* Who's coming to help?

THIS IS FOR MY BUILD.....(.190 5086 with 2x2x.25" T-bar) wanting to add 3/8 UHMW. it will be a 450hp jet boat.

https://www.youtube.com/watch?v=J9NRl-8WppI

CWAIS
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by CWAIS »

whiteriverrambo
On our High school airboat build we went ever 2" around the outside. We went every 4" ( altering from the left side to the right side of the T bar). We drilled, tapped threads and lock tight for ever bolt (or Screw).
No Expert but looks Great and had great help! Bolts came from Albanycountyfasteners.com, best prices that i could find. I get discounts in the mail so tell me before you order and I will see if I have a discount code for you to use. We did not use any adhesive so I'm not sure about that.
Watched your other videos, very NICE!!!
Chuck

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Whitebear
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Whitebear »

From commercial airboat perspective and a fleet of 35-50 Aluminum airboats in severe duty we found that rivets were the least sensitive to hole size of the three types of fasteners you mentioned. Rivets are just as easy to tighten if one works lose as bolts are. In my personal boats, mostly fibreglass I used through bolts with washers and nyloc nuts on the inside of the hulls.

No matter what you use technique and experience will make a significant difference.
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keebo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by keebo »

The fasteners are a matter of preference, I like rivets. Using screws and letting them tap theirselves into the aluminum is the best way to do it by yourself, bolting it on with nylocs is fine too. The pattern I use is 2" on perimeter and 6x6 or 8x8 through the field, fastening to the skin not the Tbars. You can buy the screws at any hardware store or airboat shop, Some might but I don't use adhesive. Putting it on a v hull will be harder then the flat hulls we use but can be done. Nobody's coming to help since you don't have your location posted. :D Good luck with your build, looks good so far in your video.
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whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

thanks for the post fella's im leaning torwards the rivets, thanks for watching the video. Im trying to video the whole build, got a long way to go. im in Salem,Indiana no airboat shop within 1500miles of me lol. Im buying a 96"x18' sheet of poly from a semi truck uhmw installer. ill have him plastic weld the nose after its all in place. sorry ill try to get my profile filled out.

whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

leaning towards rivets. can someone make a suggestion on size hardness and shape? counter sunk into 3/8 and thru 3/16 5086. also would need a air hammer and dolly choice.

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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Whitebear »

We used cheap air chisels and ground the chisel flat. I think today an air chisel set comes with a flat one in the kit. Backup dolly was a 2# ball peen hammer.

The problem we found with hard rivets, in our application, was that when we had to remove the poly next time if ya got too aggressive with the cutter (we made our own) you could tear the hull sheet if the rivet didn't cut with the impact. Never saw it happen with the softer rivets.
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Dr.Dan »

I enjoyed the video. It looks like a nice build.

I'm in the process of building my first airboat right now. I haven't got the poly on yet so take all this with a grain of salt:

My plan is rivets. I have used rivets for other aluminum fabrication things in the past. Once you do a few, rivets are really nice and easy.

I chose soft rivets, they go in much easier. I think they'll be plenty durable.

Based on advice from this site, I'm not planning on countersinking. Apparently the tapered heads will countersink themselves when driven. I haven't tested this yet.

For a rivet gun, I have a relatively cheap one from eastwood. It works pretty well. I've also driven them with an air chisel. It works fine but lacks a bit of control of the rivet gun.

Head sets for the rivet guns can be found cheap lots of places. Mine came from ebay and are of decent quality. It has various sized round heads and a flat head, all polished nicely.

For bucking I sometimes use a small sledge, or autobody dolly. I also have a heavy sledge head that I've polished the faces. It works well.

For rivet sizing, there is a good free app for the iphone: RivetSizer You just enter the size of the materials and it tells you the size. 0.190 + 3/8 would be AD6-13.5

My build is on the slow track, so I won't be able to try my plan for a month or two. Best of luck

dd

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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Garrett0742 »

I am in the process of reinstalling ploymer on my boat and I removed the old polymer and cut all of
The bolts off and now I'm tryin to remove the old 5200. My question is could I sand it down, brush on new 5200 and put the new polymer on? It is a serious pain to grind, sand all of the 5200 off down to the bare aluminum. I grinded all bad spots and smoothed it out. I planned on smoothing it all out and making sure it was all abrasive so the 5200 would stick.
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Edge1
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Edge1 »

There's a product called debond that dissolves 5200 you might try. Save you some elbow grease sanding that old stuff off.

Garrett0742
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Garrett0742 »

Ok I'll check that out. Thanks. I know I'm getting tired lol
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whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

anybody who uses bolts......have you used bonded sealing washers?
https://www.boltdepot.com/Product-Detai ... duct=15212

or one of these Greenlee combination drill, tap bits?
http://www.westsidewholesale.com/greenl ... oCMxzw_wcB

whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

on to spacing...... I imagine if I rivet I need them spaced closer together vs. bolting. if I bolt and use 1/4x20 then im thinking every 6" around perimeter and a 6"x9" grid. this would be 350 holes. would this be within reason?

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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by bbstimey »

2" around perimeter usually a 6" pattern in the field
you won"t use anymore rivets than bolts. rivets is way easier and better on your feet
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pipedog
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by pipedog »

I've put poly on both ways and rivets is a lot easier. Also you want the poly to be hot so it expands during the fastening process, so when it cools off it will be tight and you won't end up with any bubbles in it. Good luck with your build :salute:
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whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

had to come back and thank yall. I am getting close to doing my poly. I am going to go with 1/4 20 bolts, bonded washers, and brass nyloc nuts. will probably be loc-tite each fastener and for the pattern im going 2" perimeter and 6x6 grid. plan on doing a install video when I get there so "Subscribe".

latest video- https://www.youtube.com/watch?v=yLf-mi189bM

whiteriverrambo
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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by whiteriverrambo »

im looking at countersink tools. somebody educate me.........80 or 100degree? do I get 3/8, 7/16, or like a #20, #30 or what?
again im using standard 1/4x20thread 318SS hardware.
wanting to buy a nice "microstop" unit.

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Re: Poly Install.........Screws,Rivets, or Bolts?

Post by Gary S »

Get the one that matches the screw you are using.

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