CATALYST RANGES FOR RESINS
Catalyst Ranges for 301, 301W, 302, 303 & 305 Resins
- Uses LBI-321 MEKP
- 5-15cc per Quart of Resin, 20-60cc per Gallon of Resin.
- This range is between .5%-2%
Catalyst Ranges for 304, 306, 307, 308 & 309 ISO Gelcoats
- Uses LBI-321 MEKP
- 10-20cc per Quart of Resin, 40-80cc per Gallon of Gelcoat.
- This range is between 1%-2%.
Catalyst Ranges for 901, 902, 585, 555 & H197P Resins
- Uses LBI-391 MEKP(H197P uses LBI-321)
- 15-30cc MEKP per quart of resin, 60-120cc MEKP per Gallon of Resin.
- This range is between 1.5%-3.0%
A Guide for Catalyst Levels
- The amount of catalyst added to the resin determines how hot the reaction gets.
- Heat is what causes the resin to cure.
- In cool weather (55-60F) catalyze resins in the mid to high range:
- 301, 301W, 302, 303 & 305 resins at 10-15cc per quart, 40-60cc per gallon
- ISO Gelcoats at 15-20cc per quart, 60-80cc per gallon
- 901, 902, 585, 555 & H197P 20-30cc per quart, 80-120cc per gallon
- In hot weather (75-90F) catalyze resins in the low to mid range:
- 301, 301W, 302, 303 & 305 5-10cc per quart, 20-40cc per gallon
- ISO Gelcoats 10-15cc per quart, 40-60cc per gallon
- 901, 902, 585, 555 & H197P 15-20cc per quart, 60-80cc per gallon.
- Fiberglassing below 50F is not recommended unless you have some method of warming the resins and materials to room temperature(See Fiberglassing in Cold Weather Tech Guide)
- If your resin is still hardening too quickly in higher temperatures try chilling your resin in a cooler or refrigerator(DO NOT FREEZE YOUR RESIN!)
- REMEMBER: THE MORE CATALYST YOU USE AT A GIVEN TEMPERATURE THE FASTER THE CURE!
- NEVER CATALYZE RESIN BELOW THE MINIMUM RECOMMENDED QUANTITY!
- BE ORGANIZED AND HAVE ALL YOUR TOOLS AND SUPPLIES READY! ONCE CATALYZED, RESIN WAITS FOR NO ONE!
This Post Has 3 Comments
We are building a boat that has a flat deck area that measures 10′ x 25′, marine plywood(douglass fir) and we will need to have it water proof and resistant to abrasion. Just from info on your site we are leaning toward the vinylester resin and mat with the glass filled gelcoat. this boat will be in salt water exclusively and will have the deck scrubbed after each use, shells sand, and debris. We will also need to bed the seams in the joints prior to glassing and would like your input on the best bedding compound to use before glassing.
Thanks,
Randy
Hi Randy!
For durability I would definitely recommend vinylester for the decks. The vinylester gelcoat on its own is highly abrasion resistant, water resistant and chemical resistant. The addition of the glass makes it resist the galvanic effect(which is the electrical current generated by the bottom of the boat as it moves thru the water).
The bedding/bonding putty you can use could be either a vinylester or polyester based. Generally if the putty is going to be glassed over and sealed in most folks go with the poly based. If you want the extra strength go with the vinylester putty.
If you know what your lay-up schedule is going to be I can give you a rough calculation of the amount of resin you’ll need.
What is the result of not catalyzing with enough mekp, and how can I correct that situation?