That doesn’t sound right to me. Don’t mix anything until you get more input. Expert opinion probably on the way. Or, Check the archives. I used about 5-8 cc of catalyst in a quart of resin before I switched to uv resin. 14 grams of catalyst is 14,000 mgs. Mike
Tentoze, According to a chart in Essential Surfing by George Orbelian, for one quart of resin use 7cc catalyst for a 3/4% mix. For a 1% mix, use 9cc. For a 1/2% mix, use 5cc.
I’ve found those formulas to work pretty good at around 70 degrees F. Adjust accordingly if it’s lower or higher. He also states, “Do not attempt to apply resins below 60 degrees F or above 90 degrees F.” Doug
ya might want to brush up on those math skills. 50% is half of 100%, but it is NOT “1/2 %”. 1/2 % = half of 1% = 0.5%. the way you wrote it indicated that you were using 100 times the appropriate amount (50% as opposed to 0.5%).
ya might want to brush up on those math skills. 50% is half of 100%, but it is NOT “1/2 %”. 1/2 % = half of 1% = 0.5%. the way you wrote it indicated that you were using 100 times the appropriate amount (50% as opposed to 0.5%). From Chaos comes Clarity
I’m not really sure much clarity came from that chaos…
Regardless… he found out how much cat to use… he WROTE IT DOWN (?) and can go from there on number 2.
Chirren, please. My information from Ted at Fiberglass Hawaii sez the poly resin is strongest with a catalyst ratio of about one percent. However, that’s too fast for garage glassing in Honolulu, where the ambient temp/humidity are both in the 80s. I use about 0.75 percent to 9.875 percent and move the squeegee quickly.
Let’s lay down the basics, then, from which you can create your own catalyst chart.
One quart resin = 946 cubic centimeters or 946 cc so
1% catalyst is then 9.46, say 9.5 cc
(I use a quart to lam a nine footer with six ounce cloth)
but if you find this has too short pot life, use .75% catalyst or
.75 x 9.5 = 7.125 cc per quart.
I measure my resin by the cupful, and 4 cups = 1 quart, so 1 cup witih 1% catalyst requires 2.36 cc; at .75% a cup of resin uses 1.77 cc.
On the wall of my garage is my catalyst chart, with cups of resin in the first column, and concentrations across the top row. For each quantity of resin I can look up and see how much catalyst to put in for 0.5%, 0.75%, 0.875% and 1%.
Soooo… 1. get (and use) a syringe or graduated cylinder from the drugstore. 2. Write down how much resin you use and how much catalyst for various size boards. 3. Pretty soon you’ll know exactly how much to use for various size boards, and you can compensate for hot and cold weather days.
I’ve been doing it awhile and it has, at times, been a real bugaboo. Proportions and cure times seem to vary with every brand. Some resins have a little accellerator (cobalt) in them and need less catalyst to kick. Even the age of the catalyst can have an affect on cure time. Certainly, as has been pointed out, temperature can affect cure time.
For future boards, UV resin avoids all this math and is a very good way to go. I have no high tech lights or anything - open the garage door and put the glassed board in the sun. If doing cutlaps, just don’t leave in sun too long. Cutting laps that are fully cured (and it happens quickly with UV resin) can be a pain.
The chart in “Essential Surfing” is the same one that most suppliers publish. I use half the catalyst the chart says at 1% for laminating and the full amount for hotcoats and gloss. I’ve used this for years without problems even with opaque pigments. This works for me at 75 degrees average and batches no bigger than 18 oz.