Resin Hardening too fast

Brandon Bolling

Brandon Bolling

Active member
I am replacing the transom on a fiberglass, 14ft, flat bottom. The new transom is set and I just have to put the finish layers of glass to complete it. The problem is when I put a full piece of cloth over the entire transom, the resin gets gobbed up before I am done wetting the entire thing. I was thinking that I just use less hardner but I don't know the ratio that still makes it effective and strong but has a longer setting time so I can wet the entire piece. Any help would be very much appreciated. Thanks in advance.
 
What kind of resin?

Polyester resin you can do that. (use less hardner)

If you are using Epoxy do not change the mix ratio.

Eric
 
If you were working in a shaded area when your resin was going off like you describe then I would cut the hardner in half. Excess hardner will work it's way out and not be a problem. Too little hardner will leave the chemical change incomplete and is not what we were looking for. We look for a potlife of 15 to 20 minutes. Temperature, humidity and chemical make up of the resin and hardner all determine the ratio. How thick the layup is will also determine the amount of heat it will create also affecting cure time and ability to work the layup. Yep! Pretty much trial and error. :^)

A couple of things to watch out for:

Look for that 15 to 20 min. pot life, adjust your catalyst ratio to suit.

Work in the shade. Stay out of direct sunlight. With a blended resin made for sunlight you can layup in the sun but it's still a BIG PITA.

Work fast. Use a paint roller to apply the resin quickly to large surfaces. Resin will cure slower when it is spread out. Pull your roller or brush out of your resin when you have to stop for whatever, the build up of resin in the roller or brush will cure faster and create heat which will affect potlife.

Store your resin in a cool dark place to keep it as cool as possible until you use it.

Hope this helps.

Eric
 
Thanks a lot Eric, I really appreciate your help. I have taken over the garage so I am always in the shade and I leave the main door and the access door open for ventilation. I never thought of using a roller, its pretty obvious now but sometimes the obvious is not so......well you know. I have the next 2 days off and I will be working on my trial and error. Pictures to follow. Thanks again to everyone for there help. I appreciate it.

-Brandon
 
I am replacing the transom on a fiberglass, 14ft, flat bottom. The new transom is set and I just have to put the finish layers of glass to complete it. The problem is when I put a full piece of cloth over the entire transom, the resin gets gobbed up before I am done wetting the entire thing. I was thinking that I just use less hardner but I don't know the ratio that still makes it effective and strong but has a longer setting time so I can wet the entire piece. Any help would be very much appreciated. Thanks in advance.
Click to expand...

You want a catalyst level around 2% in order to get the proper hardening and chemical linking.

Our solution for laminating boats is to use a 30% catalyst. It will still give you the proper hardening but is 30% less reactive and that slows down the curing, thus allowing us time to laminate properly.

Also a good idea to work with smaller pieces of CSM (chopped strand mat) and follow that with cloth. Do NOT eliminate the CSM layer. The CSM is required for Polyester in order to hold a bulk of resin against the substrate to effect a proper bond.

Wet out, as previously stated by others, using a 4" paint roller and follow that with a ribbed laminating roller. Pre-wet your transom area and then pre-wet your CSM (or you can use Knytex 1708). When wetted, lay the cloth on the transom and begin rolling it smooth and removing bubbles.

Holler with any other questions.
Lou
www.lockstockbarrell.com
 
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