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UHMW Handling Question

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Re: UHMW Handling Question

Postby Ahusk » Thu Sep 12, 2019 8:22 pm

You are over thinking it. Just do it. Chine walk is just when the boat starts skipping like a rock when you turn sharp. Chances are you will be fine. What brand is your mini? Most boats don't do it. Mine is super flat and has no reverse chine for grip. You over steer the ability of the single strake to Grip and it starts skipping. No big deal.
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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Sep 13, 2019 11:34 am

Thanks Ahusk, that’s exactly how I was hoping someone would lay it out for me, I do agree I am overthinking this. With that said, where did you source your uhmw, I’m about 2 hours north of you? Also what did you use for fasteners, taps, sealant,and caps to plug the holes, and where did you buy them from? My boat is homemade and not like any other mini design I’ve seen, I bought it from a guy who claimed to have worked for Rogue Marine before building on his own. It’s very sturdy, I love the layout for fishing, I love the handling, but the welds are ugly!!! I bought the boat with a Tigershark 640cc in it for $4000, and replaced it with the same intake you have and a 951 Seadoo. I’ll try to get some pics, but The quality and design are not at all similar to any boats I’ve seen on this site so I have been hesitant to post pics! Anyway, the bottom is probably a little higher dead rise than yours, and not quite as powerful or fast, so I am hoping I won’t get chine walk near as much, and most of the tight turning I do as slow as possible while keeping on step except for a few instances.
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Re: UHMW Handling Question

Postby SkinnyH2O » Wed Sep 18, 2019 1:02 pm

Anyone feel strongly about 1/2” vs 3/8”, or wether a small overlapping keel strip is necessary? Weight is not an issue, 4x10’ sheet of both are only about 20 lbs difference, and cost is not an issue at $290 vs $320. The only advantage of the 3/8” I can foresee is being a little more malleable and possibly conforming to my radius bottom better at install. I don’t think this will be all that difficult with 1/2 given I will put a slightly overbent bend to help before install. Any advice is much appreciated. I’m looking at 5/16” x 1 1/4” length stainless bolts with rubber backed washers and zinc grade 8 nylock nuts for fastening.
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Re: UHMW Handling Question

Postby jetboatwanabe » Wed Sep 18, 2019 8:04 pm

SkinnyH2O wrote:Anyone feel strongly about 1/2” vs 3/8”, or wether a small overlapping keel strip is necessary? Weight is not an issue, 4x10’ sheet of both are only about 20 lbs difference, and cost is not an issue at $290 vs $320. The only advantage of the 3/8” I can foresee is being a little more malleable and possibly conforming to my radius bottom better at install. I don’t think this will be all that difficult with 1/2 given I will put a slightly overbent bend to help before install. Any advice is much appreciated. I’m looking at 5/16” x 1 1/4” length stainless bolts with rubber backed washers and zinc grade 8 nylock nuts for fastening.



May I ask how much the sheets weight??? at 4x10' :Drink1: :bash:
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Re: UHMW Handling Question

Postby SkinnyH2O » Wed Sep 18, 2019 9:34 pm

1.84 vs 2.42 lbs/sq ft, so if I use roughly the whole sheet it’s 73.6 vs 96.8 lbs. I normally would always go overkill, but being a radius bottom I have a feeling I may want a little more flexibility at install. I talked to Doug Riddle and he says almost all their minis are 3/8 and it is very tough, I guess I’m looking for other people to agree or disagree that 3/8 is fine for a 12 footer, or wether it’s “night and day” difference.
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Re: UHMW Handling Question

Postby jetboatwanabe » Thu Sep 19, 2019 8:38 pm

SkinnyH2O wrote:1.84 vs 2.42 lbs/sq ft, so if I use roughly the whole sheet it’s 73.6 vs 96.8 lbs. I normally would always go overkill, but being a radius bottom I have a feeling I may want a little more flexibility at install. I talked to Doug Riddle and he says almost all their minis are 3/8 and it is very tough, I guess I’m looking for other people to agree or disagree that 3/8 is fine for a 12 footer, or wether it’s “night and day” difference.


https://youtu.be/JL9eqQ9H7M8

Give this a watch Sir!! :Drink1: :bash:
:chicken:
viewtopic.php?f=17&t=23187&p=185475#p185462
This thread is a good read also.

18 mm is 0.70866 thick darn near 3/4 thick plus uhmw strakes on top of that with no damage from those hits!!! :Drink:
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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Sep 20, 2019 8:52 am

Those hits are harder than anything I’ve ever seen. I am now convinced to go with 1/2”, but not because I want to take hits like that, mainly what convinced me was the fact that he used 18mm and had no problem getting it on there. I was very concerned about recreating the keel and having the 2 split ends of uhmw meet up perfectly at the keel in the front section, but clearly it does not look perfect on his pics of the bottom later in his thread. Thanks Tom!
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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Sep 20, 2019 8:59 am

Any other words of wisdom before I get started? I’m gonna over brake the keel a little, and maybe try not to brake the last 2 inches before the intake? I assume everyone recommends skinning over the last 1.5” of the hull that hangs past the transom that is bent for trimming, I assume this will not be effective for trimming anymore if I was to leave it uncovered? Does anyone hear the uhmw before braking it or applying it to the hull?
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Re: UHMW Handling Question

Postby jetboatwanabe » Fri Sep 20, 2019 7:52 pm

SkinnyH2O wrote:Any other words of wisdom before I get started? I’m gonna over brake the keel a little, and maybe try not to brake the last 2 inches before the intake? I assume everyone recommends skinning over the last 1.5” of the hull that hangs past the transom that is bent for trimming, I assume this will not be effective for trimming anymore if I was to leave it uncovered? Does anyone hear the uhmw before braking it or applying it to the hull?




yes you want to be in a warm space when you install as it really grows with heat. if you install cold it will pucker up and get wavy when it gets warm and try's to grow. :Drink1: :bash:
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Re: UHMW Handling Question

Postby Ahusk » Fri Sep 20, 2019 9:17 pm

Chicken heat lamps work wonders. Over break and push the center down. Add 3m 8115 to your list. Make sure your bolts are countersunk at least an 1/8 and definitely use 1/2 inch Uhmw.
Last edited by Ahusk on Sat Sep 21, 2019 7:26 am, edited 1 time in total.
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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Sep 20, 2019 11:23 pm

Wow, never considered that, now you’ve really got me scared, that would be horrible. Exactly how big of an issue is this, it’s gonna be in the 60s in a few days when I do this, should I try and make a makeshift room around my boat in my shop to heat this considerably.
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Re: UHMW Handling Question

Postby SkinnyH2O » Sun Sep 22, 2019 1:04 pm

So I’ve decided to use the heat lamps in my shop without an enclosure , I think this should be fine with it being in the 60s this week. I don’t think I’m going to use any bonding agent, I talked to Doug Riddle and he doesn’t use any, in fact he doesn’t even recommend sealant on the bolts, says it’s unnecessary and makes repairs and replacement a pain at times. I’m not sure about the sealant on bolts, I may use a small amount of RTV because my boat is not brand new and the bottom is lightly dented in a couple spots. I’m a little torn on wether to recess the tapered head screw more than is required to make the screw head flush with the uhmw, are you(Ahusk) going beyond what is required to make it flush so you can fill the holes in like you did on your boat? Could see how sealing or capping any screw heads that are not completely flush might make a difference with drag, but I wouldn’t think it would make much difference if they are flush. Guess the other issue is they might be more vulnerable from impact if not recessed, but I have to say that I’ve never seen another boat besides yours that was bolted with overlying caps or sealant of some sort, especially not any that are in these videos of crazy impact like the one jetboatwannabe linked a few posts ago, I have to think there is a reason. Anyone else cap or put sealant on the screw heads to cap/cover them.
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Re: UHMW Handling Question

Postby Ahusk » Sun Sep 22, 2019 3:47 pm

My 15ft full interior boat only lost a couple miles an hour, maybe, and still easily does over 50 with Uhmw. When you flush up those bolt heads and run it across some rocks what going to happen to those bolts? To each his own man. Boat builders including Doug have been doing things in certain ways for a lot of years and it certainly works. They are in the business to make money. Doesn't mean there's not different or better ways to skin that cat.
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Re: UHMW Handling Question

Postby SkinnyH2O » Mon Sep 23, 2019 5:13 pm

I definitely would like the reduced drag of sealing them and the less vulnerable bolt head, but my only concern is losing some of the purchase the tapered bolt head has, effectively reducing the thickness by an 1/8” theoretically making it more vulnerable to heavy impacts, I have read several threads of the bolt head popping through the uhmw and leaving a gaping hole behind , which seemed harder to fix then replacing a broken bolt, I guess you could just seal the hole and place a new drilled/tapped bolt next to it. Don’t get me wrong, I think the way you have done it is innovative and serves a purpose, I guess I just wanted to see if anyone else who takes big impact s like on that video had any experience sealing them, as much as I don’t plan on taking any hits like that regularly, I guess I would like it to withstand it if i did, because knowing me I probably will. Have you taken any big hits like in that video, if so, have you had any broken bolts or bolts popped through? I really appreciate your input Ahusk, my boat bottom is closest to yours and I have mimicked just about every part of your install and used just about all your suggestions. If I do go the route of sealing them, can you describe the process briefly, I’m using 5/16” bolts, so did you use a depth limiting counter sink bit set an additional 1/8” deeper then flush and then seal with the sealant you suggested earlier? Is that the sealant you used on the bolts as well, how did you apply that, holes and bolts/washers/nuts, or sparingly on threads only? Thanks again, I picked up my sheet today and am getting it cut and bent in the morning, wish me luck!
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Re: UHMW Handling Question

Postby Ahusk » Mon Sep 23, 2019 10:13 pm

I will be happy to answer all that but you will have to wait until morning when I have a computer to type that much. :)
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Re: UHMW Handling Question

Postby jetboatwanabe » Mon Sep 23, 2019 11:11 pm

Now if you really want to see a boat bashing watch these. :Drink1: :bash:
:chicken:

https://youtu.be/4ip-JY9GkeI

https://youtu.be/lsy1C5sWtX0
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Re: UHMW Handling Question

Postby SkinnyH2O » Wed Oct 09, 2019 1:01 pm

Well, finally bit the bullet and drilled 200 holes in my boat and attached a sheet of 1/2” uhmw from chine to chine. Unbelievable! So much for bolt holes causing drag, somehow I gained 2mph! I’m guessing I compensated for any loss of speed by finally cleaning up my intake/suction housing welds smoothing out a couple weld lines before the intake, either way I’m stoked! Handles as good as ever, no chine walk, I left about a 1/2” uncovered before the chines, in case I want to cap them with uhmw, but I doubt I will after driving it. I also don’t know how to explain how I don’t have any more porpoising even with a passenger, with my trim all the way nose-up and my bendable trim extension completely covered? Oh well, I won’t complain about that. I also didn’t use any sealant anywhere whatsoever, no leaks, even after hammering it even catching air a few times, I was worried they might loosen and leak after impact. Anyway, thanks again everyone for all your help, I’ll try to post some pics later.
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Re: UHMW Handling Question

Postby jetboatwanabe » Fri Oct 11, 2019 8:54 pm

just a reminder Sir its later!!! picks??? glad you solved problems and have protection to boot, ye ha. :Drink1: :bash:
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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Oct 18, 2019 11:54 am

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Re: UHMW Handling Question

Postby SkinnyH2O » Fri Oct 18, 2019 11:55 am

Install

[img]https://photos.app.goo.gl/g24VgQ9AspvgzhDp8[/url]
Image
Image
[img]https://photos.app.goo.gl/7JqvMozf6Rwszrt99[/
Intake before cleaning it up/smoothing it out
Image
Intake after
Image
Bent uhmw
Image
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