Fiberglass Worry

[revjim]

I mixed up my fiberglass and put a little extra hardener in it...refenforcing the splashwell...laid the matte down yesterday...it is still tacky and wet feeling. It is 55 degrees here..lows 35...will this just take longer with the colder weather?? thanks.

 

[Matrex]

Re: Fiberglass Worry

I have the same concern - it is getting below freezing overnight here.
I suppose every brand will differ - here is what the docs for the EPOXY I am using say:

Time Table:
For a 300 ml mixture

?C ?F Pot Life Cure time (90%)
10? 50? 15 min 24 hours
20? 68? 10 min 12 hours
30? 86? 5 min 6 hours

 

[jonesg]

Re: Fiberglass Worry

Hit it with a hair dryer or put halogen lamps on it,
I'm still doing resin work and its freezing at nite.

 

[ondarvr]

Re: Fiberglass Worry

Yes, use lights or some sort of heat and the surface should feel slightly tacky, not soft though. The other thing is what do you mean by "a little extra hardener", a little more may be OK, but what level were you at to start with?

 

[180shabah]

Re: Fiberglass Worry

How much did you mix, and how much is "a little extra"?

 

[ondarvr]

Re: Fiberglass Worry

There were Questions about your project in your other thread that were never answered. The main one is, what is it you're actually trying to do?

 

[revjim]

Re: Fiberglass Worry

Okay...it is still tacky...not wet...put another layer of mattte and resin on...covered it and I have a hairdryer on it...HOW LONG WITH THE HAIRDRYER??? thanks...not shouting.

 

[bowman316]

Re: Fiberglass Worry

you need to let the first layer dry before you put on a second layer.
i know a professional fiberglass guy, who can dry glass in an hour or so with heat lamps.
he touched up some glass, by putting another sheet on, and painted it in one saturday afternoon.
he used heat lamps

 

[revjim]

Re: Fiberglass Worry

Just got done checking it and the thing is rock hard...i hope that means what is underneath cured as well...what do you guys think...guess the hair dryer worked!

 

[mphy98]

Re: Fiberglass Worry

in the future, glass should be heated with a heat gun or a hair dryer when the temp is below 65*F this comes from our guys in the bodyshop at the dealership. i cut out the seat risers from my 79 thundercraft and reglassed where the risers were. it was 55* and was not hardening. the guys told me to do this to activate the resin. once i got it activated it started to harden with heat on its own. accrding to our guys if you do not activate the glass, it will never harden.

 

[oops!]

Re: Fiberglass Worry

There were Questions about your project in your other thread that were never answered. The main one is, what is it you're actually trying to do?

rev jim........in order for us to help.....you gotta help us help you......you are repairing a crack on a transom.......but there may be more to it than you are doing.

if you can take some pics and answer some questions ....then we can help you.......but you may be putting a band aid on a big chunk of cancer.

 

[BillP]

Re: Fiberglass Worry

If its still tacky a day later you didn't over catalyze it...but is it soft to the point of being rubbery or just tacky on the surface? If just tacky its probably laminating resin and is meant to stay tacky so no sanding is needed for glassing later. If soft and rubbery after a day or two the glass job is highly compromised and adding heat really won't help. Polyester has to initially kick (hard but still has to reach the max strength) within a certain time to get the max strength and I've never seen mfg charts that showed initial kick time to be more than a few hrs. Not that it can't be longer but I've personally never seen it. When to that point there is nothing that will restore the strength. Glassing over can give strength but it will still leave a soft under layer and adhesion of the soft layer might be a problem. Only in the long term (months to yrs) will soft polyester jobs like that get "dry".

Perhaps the local resident resin expert here can provide a poly kick time graph from the company he works for which will give you proof on how it works. The graphs I've used show temp, humidity, catalyst %, initial kick time, final cure time and hardness range...from minutes to weeks. You add or subtract values based on local weather conditions.

bp