laminate schedule for e-glass, kevlar and PLascore

I've seen allusions to Kevlar and e-glass used in laminations with the polypro Plascore to reduce impact and abrasion in the construction of drift boats. Nowhere I could find was there discussion of what weight fiberglass and Kevlar fabric were used and how many layers or the distribution of them. How would the schedule change for the sides? I wish to build a drift boat and later a lightweight flats boat with this new composite panel as core.

 

You can find your answer in the DNV related rules.

 

This depends on what kind of water,size of boat, how thick of core?...I've seen anywhere from a couple of layers of 6oz to a couple of 22oz triax.Most just use 6oz woven kevlar as the first inside layer.I dont think its needed but it seems to be popular.

 

Thanks for the input. I went to the DNV site but only found topics related to certification. I must be missing something. I will use 1/2" polypro Plascore and see that it is used in drift boats out west. I was wondering what weights of cloth were used for that purpose. I need to keep the boats light but also will hit rocks and logs in the river occasionally.

 

Do some googling.

Ive seen plenty of panel testing , for impact resistance, using various fibers on drift boats.


Comprehend the method in their madness then Make test panels and destroy them in a scientific way.

If I remember correctly Sglass fiber performed the best.

 

I used to build drift boats and now I supply the major DB manufactures in the west.

What exactly is it you want to do with the boat (I know, float down rivers, but Class of rivers I, II, III, IV, etc and type of bottom can make a difference), several different methods of construction are used depending on if it is a one off custom boat, or for production.

 

In regards to post # 1 are you the gentlemen who once was building Drift boats in Baldwin Mich , using Plascore products with no mold ....what so ever .......... and just curious why would you want to use Kevlar in your build considering in post # 3 Tungsten has already mentioned the very same thing , and if strength is your reasoning for using Kevlar other then the look ...............why not use S-Glass instead ?

 

There is not only certificate on DNV site, it has boat design and building standard too.

 

laminate scedule for e-glass, kevlar and Plascore

Thank you for the advice. I would be delighted to use s-glass instead; it sounds appropriate for my area as our trout rivers are not as rocky or rollicking as yours out west. Glass would be better for the "bruising" that I anticipate as well as the rough treatment a guide's boat will receive. They typically finish the day by hooking a tow line to the boweye and pulling it up the steps with their truck. Perhaps the kevlar felt drag strips would be sufficient. I am from north of the fellow who makes those excellent Stealthcraft drift boats near Baldwin. He advertises the use of kevlar in his lay-up. I visited a site where the builders would employ upwards of 40 ounces of glass and one layer of kevlar externally for the bottom over 3/4" Plascore polypro. Their intent was to float the Grand Canyon...not my plan. Now that I've seen the schedule with the "most" laminates used, I wonder what is considered the least amount? I am building a truck cap with 1/2" Plascore and 10 oz. e-glass in and out and have yet to hit it with a hammer, but I'm quite sure it won't like it. I will explore the DNV site further. MW

 

Funny thing i have been tossing around the idea of building a few Drift boats myself , and after seeing the operation in Baldwin Mich i feel i can build a much better boat with quality in mind using better materials and techniques along with trying to keep the cost down considering after viewing that operation in ( Baldwin Mich ) it reminded me more or less of a Sanford & Son kind of a hack and slash , slap it together ( garage )operation with a lack of quality to boot if you know what i mean . Funny thing the Plascore plant is in my area , and just curious are you thinking of using the same techniques in your build ?

 

I see that Fiberglasssupply .com lists sglass SA060 unidirectional and sglass SDB120 and SDB170 in 45x45 .


http://www.fiberglasssupply.com/pdf/reinforcement/KnittedFabrics.pdf

Would be worth getting a price for sglass to compare with eglass.


I dont know much about the use and design of driftboats, but These fabrics would be interesting for a small boat that must be light and rugged.

Kevlar is not friendly to boatbuilders... its difficult to work with , absorbed water and is very difficult to repair. Beware.

 

First off fiberglass supply is always very pricey and to tell you the truth in my opinion E-Glass is widely used in the industry because it is a very economical reinforcment that offers strength , light weight , and is often used in small boat construction ,but on the other hand S- Glass is the same as E-Glass but offers more strength , toughness ,and durability , opposed to E-Glass with only one draw back ........................the price or should i say it costs more .

 

There are two lines of thought on cored hulls for drift boats.

A cored hull may possibly make rowing slightly easier because of the stiffness it provides, more energy is transmitted to the water. A flexible hull bottom will slide over rocks easier with less chance of damage because it allows the portion of the hull in contact with a rock(s) to move and ride over it without having to lift the entire boat. Rock damage to the chines will be about the same with either style.
Spot loading on the tip of a rock can be very high on a rigid hull, so you are more likely to gouge the gel coat, or fracture the glass.
(DB hulls tend to have rather thick chines and comparatively thin hull bottoms and are flat, so they flex. This was added for those that don’t know what a drift is, or how its used)

I fix drift boats, and it is very easy to fix a non cored hull, you can see both sides and know what you are in for before you start. On cored hulls, like the one I fixed last week, it can be difficult to know what the extent of the problem is until everything is torn out.

In my opinion how well a DB rows and how it handles has far more to do with the hull design and weight than whether the hull is cored or not. Also, most drift boats are over built for how they get used, much of it for advertising purposes, because thicker is perceived by the potential buyer as better.

Where I launch now you can’t get down to the water, the last 20’ or so is over large river rock. Where I take out (my front yard) is a 4’ vertical wall, part of it rip rap, plus some dirt we drag them up and down each time. Been using my non cored hull like this for 20 years and it hasn’t needed repairs, its also lighter than most production boats. At one time I had a dock in a cove with a nice launch, but now after a few floods the dock is sitting in the yard and the river has moved 50’ or more into what was a nice grassy area where I had a fire pit and some chairs.

 

Wow draging a boat up some stairs would be a site,maybe some removable strips made from kevlar would work.

You asked whats the lightest laminate,I'm no pro but i've dabbled a little with the foam and glass,seams to me 18-12 oz for the inside and 20+ for the outside.With care and calm water i think it would live.On a small boat anyway.

 

mwwinklerdc,

I completed a plascore stitch-n-glue boat for duck hunting. The guy who got me started on it actually did make a drift boat using plascore as well. This is paramount...when buying your plascore pp honeycomb, make sure it has the plastic sheathing + veil if you're doing a hand layup. The sales engineer sold me the wrong product and it caused the resin to soak through the cells. I wasted a lot of resin and added unnecessary weight to the boat.

Note: I AM NO EXPERT. TAKE THIS ADVICE AT YOUR OWN RISK.

His build was 3/4" plascore on the bottom, then the sides were made of marine grade, mahogany plywood. As for the layup, if I remember correctly it was...

Inside: Bottom was kevlar. Then the entire interior was two layers of 6oz glass and a smooth coat. The seams were taped with 12 oz stitched biaxial. Then, varnish to protect from UV. The bottom was coated with non-skid Duralux bed liner (note, this stuff fumes really bad when it cures).

Outside: Bottom was kevlar. Then the entire exterior was two layers of 6oz glass and a smooth coat, THEN the entire bottom and about 4-6" up the sides was a coating of Line-X without texture. After that, paint.

Really, the people you want to talk to can be found at:

http://www.montana-riverboats.com/

They could give you much more sound advice. Also, if money isn't an object I would use 5oz kevlar tape as opposed to 12oz biaxial just for the weight savings. If you're a novice to fiberglass, just use the biaxial as YOU CAN'T SAND KEVLAR. Lastly, the guys at Raka.com are top notch. Their product is great, so are the prices. They will give you all kinds of advice over the phone even if you're not going to order that day. Mike and Larry were really helpful with my first build.