Using Fiberglass in temps under 70*

[bigheaded5]

I know the product recommends using it in temps above 70*..... Im curious as to what results in using fiberglass is say 60* or 50* weather? Has any one done it and what were the problems...if any. I could deal with longer set up time, it might even be a positive in certain situations...but worried the strength might suffer from the cooler temps.

 

[jbcurt00]

Re: Using Fiberglass in temps under 70*

Glassing below 60 isn't going to give you the bonding strength you want to trust you & yours lives w/ on a boat repair. Using more MEKP will allow the resin to kick at a lower temp, but that weakens the strength of the fiberglass laminations, so over-catalyzation's also not a good idea.

It's also important to note that it ALL has to be above 60* & stay above 60* until the resin kicks:
Boat hull @ site of glass work
Resin & hardener
Cloth/Roving/CSM/1708 etc

You can trick the resin by keeping it indoors @room temp until right before you add the MEKP to it. Tarp your work area on the boat. Heat it as needed to get above 60*, and run a halogen work light(s) near the hull/glass work site. NOT too close those lights get HOT, just close enough to throw off some heat.

If you're tarped IN the boat w/ a little bit of heat, set the work lights on the exterior side of the hull, if need be also tarp over that area. A halogen light won't do much if it's in open air & it's a breezy 10* outside. Again DON'T setup a tarp close enough to the light to overheat/char or burn your tarp, or the hull.....

 

[bigheaded5]

Re: Using Fiberglass in temps under 70*

It would be the floor of my boat I would be replacing...I can heat my shed but with a Kero heater and i dont think it would remain warm enough for it to set up for the first layer, and after the first layer is down I couldnt light the Kero heater again because of the fumes.....so sprint time it will wait...thank you

 

[Woodonglass]

Re: Using Fiberglass in temps under 70*

Get some 12" flex duct and stick the Kero Heater outside the Garage door. Lower it down to 12" and stick the duct under the door. Shoot the heat thru the duct into the garage and the fumes won't matter. You should keep the temps @70? on the substrate and the resin for 24 hours and above freezing for 72 and then you're good to go. Some 500 watt Halogen lamps tented inside the boat will put out alot of heat too

 

[KnottyBuoyz]

Re: Using Fiberglass in temps under 70*

I've had problems with epoxy slumping when trying to work in cooler temps. The epoxy will form ripples before it kicks. This is on a near vertical surface though.

You cam see the tops of the ripples sanded down on the right hand side of the pic above. The next time I did it I made a tent from Tyvek and was able to keep it warm enough with a 1500 watt heater. Working on a horizontal surface wouldn't be too bad I don't think. Just make a tent and stick a heater in there. You'd be surprised how warm a small heater will get the space.