Stringer material?

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
fletchster76
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Stringer material?

Postby fletchster76 » Sun Jan 22, 2017 5:23 pm

Got a new baby on the way so I'm gonna convert my boat over to a more family friendly ride boat. I'm gonna change hulls to a 15' viking with rod boxes. I've had it in the back yard for awhile because it needs stringers. Has 2x4 stringers now. Any opinions on best wood/material to use, would like to keep weight down but want to do it right. I used the search feature but really didn't see anything within the last few years so I figured I'd ask.
13'6" Laser, 520 conversion, 72" 3 blade ngh

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pontoon outlaw
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Re: Stringer material?

Postby pontoon outlaw » Sun Jan 22, 2017 7:17 pm

My buddy's Boat we used just regular spruce 2x4's then wrapped them good in resin :)

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mojoe
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Re: Stringer material?

Postby mojoe » Sun Jan 22, 2017 9:32 pm

As long as the wood is not pressure treated you will be fine. The resin can't absorb into and bond to PT the same.

fletchster76
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Re: Stringer material?

Postby fletchster76 » Mon Jan 23, 2017 11:39 am

Regular old spruce pine huh? That will make it cheap. I had heard a recommendation of cedar but I was dreading trying to find that in 2x4x12 and then what it would cost. Thanks for the info.
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mojoe
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Re: Stringer material?

Postby mojoe » Mon Jan 23, 2017 12:05 pm

I will preface this with the fact that I am not an expert. Only done the stringers on one boat. We used 2x4 only for the 2 stringers that the angle iron for the rigging sat on. We used 1x4 for the rest. Saved a little weight. As for the type of wood, I can't remember if it was birch or pine, but it wasn't pressure treated and it was cheap. Ran that boat for 3+ years after doing the stringers and they were still rock solid when I sold it.

The key is getting the glass tight to the stringers with no air gaps and sealing all holes completely when you install the rigging.

Rounding off the top 2 edges of the wood before glassing helps with that.


Chicken Man
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Re: Stringer material?

Postby Chicken Man » Mon Jan 23, 2017 1:33 pm

Douglas fir tight grain and light.Don't remember cost,is a little hard to find. :scratch:

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Re: Stringer material?

Postby Lwells » Mon Jan 23, 2017 2:41 pm

What way can you check stringers and to what extent is bad considered. Also, does a fiberglass boat have solid fiberglass bottom or is any wood used in between?

fletchster76
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Re: Stringer material?

Postby fletchster76 » Fri Apr 14, 2017 1:55 pm

Any of you fiberglass gurus out there have a recommendation on how many layers of mat or cloth to use when doing stringers?
13'6" Laser, 520 conversion, 72" 3 blade ngh

Gary S
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Re: Stringer material?

Postby Gary S » Sat Apr 15, 2017 7:25 am

My first choice would be high density foam. Next would be the Douglas Fir. The grain is long and straight, but like said not cheap and hard to find. Last spruce . If you have any boat builders around you, go by there and talk to them about materials. They might have some scrap left over that you can pick up reasonable. A repair shop is another place to look. You will probably be able to buy resin and cloth from them too, you will have to bring your own cans.
You will want to bed the stringers into a bedding material. I like micro balloons. They are mixed with resin and make a paste. You can also use it to fare out the bottoms and give it a radius to make it easier.
I would go alternate mat and woven twice with the second mat and woven wider than the first. You can put a third mat on top to help smooth it out and help hold it down.

fletchster76
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Re: Stringer material?

Postby fletchster76 » Sat Apr 15, 2017 9:57 pm

I went white pine. I've resined them real good. Gonna do mat then a few layers of biaxial cloth/mat. Just not sure how many layers I should do. Thinking 1 mat and 2 cloth/mat. Didn't know if I should do a 4th layer. That biaxial stuff is suppose to be pretty dang strong. Thanks for any advice.
13'6" Laser, 520 conversion, 72" 3 blade ngh


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