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Resin use
By:Paul G. Jacobson
Date: 2/16/2001, 3:53 am

: Can anyone give me an Idea of what a "tight" lay up should
: use in terms of resin ??

I think the generally accepted standard for glass cloth and epoxy resin is that the final product should be about half glass and half resin (by weight). Other fabrics are somewhere in that neighborhood, too, ranging from maybe 40% fabric and 60% resin to 60% fabric and 40% resin. You can find more exact specs from the manufacturers of the cloth and resins, but for a "ballpark" estimate I'm going to use 50/50 as my guide.

By the way, I am speaking of the completely mixed resin, which would the hardener.

You know what the cloth weighs per square yard, or square meter. If it is 6 ounce cloth, for example, a square yard should weigh about 6 ounces. Using the 50/50 ratio of glass to resin, you would optimally use 6 ounces of resin on each square yard of this cloth.

Since this amount is calculated for strength, and not for appearance, I suspect the weave of the fabric will still be apparent and the surface will have the texture of the cloth.

For the sake of appearance we would put on a bit more resin to "fill the weave", or "kill" it.

You can approximately calculate the weight of the cloth you used on your boat by looking at the amount of scrap you have left and subtracting this from the amount you bought. If you bought your cloth in 36 inch width and bought 18 yards, then the cloth should weigh 18 times 6 ounces, or a little under 7 pounds.

Epoxy resin weighs about as much as water, around 8 to 9 pounds a gallon, so for this amount of cloth you would need 3 quarts.

If you use 4 ounce cloth you would theoretically use 2/3 the amount, but in practice a honme builder uses almost the same as with 6 ounce cloth. This is because the seal coat ( the first coat) is the same amount regardless of the weight of glass cloth applied, and the top coats that fill the weave are more related to area of the boat than the weight of the cloth.

Your saving comes only on the coat that is applied when you wet out the cloth. Using your squeegee on that thinner layer of cloth means you'll apply a thinner layer of resin. It will be equal in thickness to the fabric, as the squeegee scrapes off and relocates any resin that stands above the fabric.

Hate to say this, but it is unlikely you sanded off even half a pound of weight after the sealcoat. You probably used between half a quart and a quart of resin for the seal coat. That means that the most weight you applied was only 1 to 2 pounds. Since most of it soaked into the wood, that weight is still there, doing its job of sealing the woodpores. You would have to completely sand it off to lose that weight.

So, the basic answer is that a "tight" layup might get away with 5 to 8 pounds of resin, but most people end up using about 8 or 9 pounds of resin (3 quarts to a gallon).

The easiest way to reduce weight in your boat by 5 pounds is to stand in the sun and sand the boat on a hot day. For every 1/4 pound of sanding dust you produce you'll sweat off a pound or more from the paddler. Oh, and stay away from Rehd's kitchen. I've seen the cake picture he posted, and it looks like it could add a few pounds to anyone's paddling effort :)

Hope this helps.

PGJ

Messages In This Thread

About to Fiberglass a Stripper 1st time
Arthur -- 2/8/2001, 4:13 am
Re: About to Fiberglass a Stripper 1st time
Arthur -- 2/15/2001, 5:48 am
Stiff roller--good idea.
John Monfoe -- 2/16/2001, 4:37 am
Resin use
Paul G. Jacobson -- 2/16/2001, 3:53 am
Re: Resin use
Richard Boyle -- 2/16/2001, 8:21 am
Re: About to Fiberglass a Stripper 1st time
Jim Sailer -- 2/9/2001, 9:37 am
Re: About to Fiberglass a Stripper 1st time *Pic*
Rob Macks -- 2/8/2001, 11:23 am
Re: About to Fiberglass a Stripper 1st time
Arthur -- 2/20/2001, 7:32 pm
Re: About to Fiberglass a Stripper 1st time
Rob Macks -- 2/20/2001, 10:53 pm
Re: About to Fiberglass a Stripper 1st time
Arthur -- 2/9/2001, 3:06 am
Re: About to Fiberglass a Stripper 1st time
Rob Macks -- 2/9/2001, 12:05 pm
staples/no staples
Sam McFadden -- 2/10/2001, 1:53 pm
Re: Slight Disagreement . . .
Spidey -- 2/9/2001, 10:48 pm
What you want
Nick Schade - Guillemot Kayaks -- 2/10/2001, 10:32 am
Some points
mike allen -- 2/12/2001, 12:20 pm
Re: Internal Strongback
Nick Schade - Guillemot Kayaks -- 2/13/2001, 9:39 am
Internal Strongback confined releases
mike allen -- 2/13/2001, 12:13 pm
Re: Internal Strongback confined releases
Nick Schade - Guillemot Kayaks -- 2/14/2001, 9:22 am
Re: Internal Strongback confined releases
mike allen ---> -- 2/14/2001, 11:42 am
Re: What you want
Spidey -- 2/10/2001, 12:19 pm
Re: Well said!
Don Beale -- 2/10/2001, 11:00 am
Re: Slight Disagreement . . .
Rob Macks -- 2/10/2001, 12:08 am
Re: Slight Disagreement . . .
Richard Boyle -- 2/10/2001, 8:48 am
Re: Slight Disagreement . . .
Rob Macks -- 2/10/2001, 9:37 am
Re: Fell out of my chair laughing!
Spidey -- 2/10/2001, 12:45 am
Re: Slight Disagreement . . .
Rehd -- 2/10/2001, 12:24 am
Re: Might have to..........
Rehd -- 2/9/2001, 11:25 pm
Re: uneven seal coats
Nick Schade - Guillemot Kayaks -- 2/9/2001, 6:12 pm
Re: uneven seal coats
Al Gunther -- 2/10/2001, 11:49 am
Re: About to Fiberglass a Stripper 1st time
Arthur -- 2/9/2001, 2:49 pm
Re: About to Fiberglass a Stripper 1st time
Arthur -- 2/8/2001, 9:14 pm
Re: About to Fiberglass a Stripper 1st time
Dale Frolander -- 2/8/2001, 4:16 pm
Re: About to Fiberglass a Stripper 1st time
Ray Port Angeles -- 2/10/2001, 12:09 pm
Re: About to Fiberglass a Stripper 1st time
Les Corley -- 2/8/2001, 6:57 pm
Re: About to Fiberglass a Stripper 1st time
Rob Macks -- 2/8/2001, 7:20 pm
Just in time
Angela Watson -- 2/8/2001, 12:20 pm
Re: Just in time
Angela Watson -- 2/11/2001, 7:01 pm
Re: Just in time
Don Beale -- 2/8/2001, 7:12 pm
Re: Just in time
Angela Watson -- 2/8/2001, 9:13 pm
Re: Just in time
Don Beale -- 2/9/2001, 12:06 pm
Re:Keep the FOCUS..work is good..keys,wheres my ke *NM*
Ben Staley -- 2/9/2001, 12:58 pm
Re:And remember..
Don Beale -- 2/11/2001, 12:32 pm
Re: Just in time *Pic*
Bobby Curtis -- 2/8/2001, 1:34 pm
Re: Just in time
Angela Watson -- 2/8/2001, 7:04 pm
Re: Just in time
Angela Watson -- 2/8/2001, 7:12 pm
Re: Just in time
Bobby Curtis -- 2/8/2001, 7:41 pm
Re: Just in time
Geo. Cushing -- 2/8/2001, 12:59 pm
Re: Just in time
Angela Watson -- 2/8/2001, 6:56 pm
Re: Glassing time
Ben Staley -- 2/8/2001, 12:32 pm
Glassing
Russ -- 2/8/2001, 8:44 am