how much epoxy | SouthernPaddler.com

how much epoxy

a Bald Cypress

Well-Known Member
May 7, 2007
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Northwest Louisiana
Yo, Ron

I normally order the 3 gal set from Raka. 2 - 1 mix ratio.

There is always about 1/2 of it left. SO ! boat = a bit over 1 gal of resin + 1/2 gal of hardener.

I would rather have some to spare rather than having to re-order another batch to finish up the boat. Yo can always use what is left on your next boat.
 

oldsparkey

Well-Known Member
Aug 25, 2003
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Central , Florida
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I get the 3 gallon kit and normally use about half of it on a boat. You could do it with the 1 1/2 kit but be sparing and try not to waste a lot of it.
Also you need to take into consideration the length , width and is it going to be decked ... along with the glass you are using. 3.25 tight woven will take more epoxy then normal 6 oz glass.

:lol: :lol: :lol: I used 10 oz on the bottom of one boat and it took a lot of epoxy. The type of wood also is a contributing factor , some of it ( California Red Wood in the stripper pirogue I made ) soaked epoxy up like a sponge.

Chuck.
 

oldsparkey

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Aug 25, 2003
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Central , Florida
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Kayak Jack said:
oldsparkey said:
... along with the glass you are using. 3.25 tight woven will take more epoxy then normal 6 oz glass.
We're supposed to be serious here. I would have thought the opposite about tight vs loose weave glass?

I'm no expert on the glass or how they grade it , just a back yard wood boat builder with a little experience , very little. :lol:
All I know is .....The tight woven is harder to fill and takes more ( a serious amount of ) epoxy then the normal woven glass and I have used both.
Might be because there is more glass to wet in then the normal or average weave.
Not sure if I would go so far as to call the normal ... loose woven ... since it is the average weave that sets the standard for the glass.

Chuck.
 

Kayak Jack

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Aug 26, 2003
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Okemos / East Lansing Michigan
Why would you want to use tight woven, which is more difficult to work with, and will require more epoxy, using more $ and resulting in more weight? I thought the tight woven was supposed to use less poxy and total less weight.

If what I read you saying is your experience, it runs opposite of mine. Interesting.
 

oldsparkey

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Aug 25, 2003
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Central , Florida
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Kayak Jack said:
Why would you want to use tight woven, which is more difficult to work with, and will require more epoxy, using more $ and resulting in more weight? I thought the tight woven was supposed to use less poxy and total less weight.

If what I read you saying is your experience, it runs opposite of mine. Interesting.

As far as weight .... The 14 x 30 Sasquatch from JEM Watercraft sure came out heavy by using that glass ... Yep a back breaking 30 pounds. :roll: The Sasquatch made it threw some rapids and shallows filled with all sorts of rocks without any damage , on that Texas trip , that says a lot about the glass and on how the boat was made. ( 1/8th inch plywood and tight woven glass )

I really do not wish to debate this since ( it is something that can go on forever ) it is personal choice of mine on what glass I use and the positive results I have found by using it. It works for me better then any of the rest and it is what I use for my piece of mind when paddling , even if it does take more epoxy , BIG DEAL , if you have the epoxy , No Problem.. I am not spending your money so why should you worry.

Which I think was the original question about how much epoxy does it take YOU to build a boat... I took that as meaning , when I build a boat , not you or anyone else ... when I make one since we are individuals and do things differently which is what we like to share on here....Not what you are bickering or baiting me about...If you have a different thought then tell Ron , all I can say is that making a lot of boats ( to many according to my wife ) over the past 11 years this is what I have found out. :roll:

Anyone can use what they want ever the glass they want to use and I am sure the results will be different every time just as the boats we make and the water we paddle. Anyway I would hope so , uniformity belongs in the Military , civilians can think for themselves. :D

Chuck.
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
There are many different parameters that go into the specifications for glass cloth

Fortunately, for us, most suppliers that sell to marine type applications - like boat builders - will default to those specifications that meet our application whether using vinyl polyester or epoxy, e.g. type of glass, finish on the glass, style of weaving, etc.

We're left to specify the weight and either regular weave or tight weave.

The weight is pretty much straight forward and is typically stated as the weight of glass in ounces per square yard. So 3.25 fabric has 3.25 ounces of glass per sq. yard and a 6 fabric has 6 ounces per square yard. If you're dealing in a country that has the metric system it'll be grams per square meter.

The difference in tight and regular weave is that the tows (bundle of fibers) used in the weave is different. A tight weave will use a smaller tow (bundle) for the warp and fill yarns while a regular weave will use larger tows. So tight weave will have more ends per inch than a regular weave. A tight weave 3.7 oz may have and end count of 60 X 52 whereas a regular weave of the same weight will have 24 X 22 ends per inch, but the weight of glass per square yard will be the same. The end count numbers are from Thayercraft for their fabrics, I don't know the details of your specific fabric, but expect it to be similar.

Hand lay up of glass will typically result in a range from 10 to 35% glass volume, the rest is resin. Vacuum bagging and other more precise/controlled methods can boost glass volume to 50 - 70%. Glass volumes greater than 70% can generally be considered to be resin starved. This maybe more information than anybody cares for but it does illustrate the variability of resin use on glass. Different folks get different results.
 

oldsparkey

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Aug 25, 2003
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Central , Florida
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seedtick said:
The weight is pretty much straight forward and is typically stated as the weight of glass in ounces per square yard. So 3.25 fabric has 3.25 ounces of glass per sq. yard and a 6 fabric has 6 ounces per square yard. If you're dealing in a country that has the metric system it'll be grams per square meter.

The difference in tight and regular weave is that the tows (bundle of fibers) used in the weave is different. A tight weave will use a smaller tow (bundle) for the warp and fill yarns while a regular weave will use larger tows. So tight weave will have more ends per inch than a regular weave. A tight weave 3.7 oz may have and end count of 60 X 52 whereas a regular weave of the same weight will have 24 X 22 ends per inch, but the weight of glass per square yard will be the same. The end count numbers are from Thayercraft for their fabrics, I don't know the details of your specific fabric, but expect it to be similar.


seedtick , thanks for the information.
If I read this correctly the tight woven has almost three times the end count as the regular glass in the same weight. I do know if you snag it on something when working with it , it sure does not get a gap or pull/run in it like normal weave.

Chuck.
 

Paddlin'Gator

Well-Known Member
Feb 2, 2008
148
0
Tequesta, FL
Seedtick, my experience pretty much comfirms the numbers you quoted. In single skin hulls, not composite, hand laid with multiple plies of 1 1/2 oz. mat and 24 oz. woven roving we averaged 35-40% glass to resin ratio with polester or vinylester resin, toward the higher end when the laminators squeegied carefully. Using 1708 and 1808 biaxial glass we could do a little better, but still under 50%. When vacuum bagging using biaxial glass we could exceed 50%, but had be careful not squeeze out too much resin. In our composite hulls we always used biaxial glass, vinylester resin and Airex core and vacuum bagged everything to maximize the strength to weight ratio. In some hulls we also added a layer of Kevlar in the inner and outer skins in cases where the boats were being powered for higher speeds.

I have never tried to calculate the glass to resin ration in the kinds of boats we are discussing here, but because of the need to fill the weave, I would guess it is pretty low.

Joe