Too cold for poly resin?-gctid375580

[Guest]

Tomorrow and Saturday both show a high of 59 degrees. Is that too cold for poly resin on my transom? It's possible it might get down to 39 at night. Should I hold off? Or can I make this work?

Greg

[dmcb]

Heat makes it kick. You could but more hardener in the mix and heat it a bit. Be careful on the heat. Don't overdo it.

I know you have a weekend and want to use it.

Make a tent over the area and get some heat to it.

I would try to warm the area first also but if it is to hot the resin will quickly harden and reduce work time. Think room temp on a warm day.

Doug

[2850Bounty]

Greg, dougle check me on this, but I believe the minimum working temperature is 65* or so. You can use heat lamps, but I'm not convinced that you could provide even heat doing this. Plus, the components should actually be at/near this temperature when you begin.

So if you do use heat of some source, perhaps monitor the surface temperatures and working area temperature.

There will also be a recommended catylist ratio for each working temperature range. Follow this closely.

If the ratio is incorrect for the ambient temperature, the resin may go off too early, or too late... or not at all.

I'd highly recommend that you use a catylist dispensing bottle.

With a known amount of resin to be mixed, the correct amount of catylist can be added very easily and quickly. No messing around with small plastic cups, etc.

Just squeeze the bottle, and a dip tube forces the catylist up and into the smaller graduated container above.



This is similar to what I have.



Either should work OK.

.

[Guest]

Be very careful not to add too much hardener. It will dramatically cut your working time.

[Guest]

I agree with the advice given so far.

The wider the temperature ranges are from day to night, and the colder the day is, the harder it is to get your ratios just right. An experience pro might get his ratio correct the first time, and have it kick before the evening started to cool. If you're a resin rookie, wait for warmer days, or control your work area with tarps and heat.

[yachtman]

You can heat it with lights but it really should be closer to 65-70. If you catylize it too much you can also change the properties of the resin and it wont be as strong. I would wait. I am having the same problem chomping at the bit to work on it but the temps arent just there yet. Small areas would be fine as they can be heated. Large areas are a different story. The night tem shouldnt make a difference as it should already be cured in a half hours time. If not its too cold.

You couod tarp it and use a propane heater or such. Be careful if you have flamables around. Me persoally i would wait. Oh yeah im already waiting

[2850Bounty]

yachtman wrote:
You can heat it with lights but it really should be closer to 65-70. If you caylize it too much you can also change the properties of the resin and it wont be as strong. I would wait.

Excellent point!

Sheesh... now I have to give out some more Rep Power points!

.

[Guest]

Although it kills me to do it, I think I'm going to wait. It's so hard because after the transom goes back together I still need to put the engine back in and figure out where everything is going to go. :-(

Greg

[Guest]

Well here's my take even though I am certainly no expert; as has been stated, too much catalyst is not good. When I did my transom OAT was around 50*F If I had waited for 65* around here I would have waited until June or July.

I heated the compartment and made sure my resin was at room temperature. Sometimes it took longer to kick so I would have to walk away and leave it alone for several hours but it always kicked. Better IMO to take longer to kick than kick too soon especially if you're new to working poly resin.

Also you can always let it sit in the mixing can a few minutes longer and watch it closely. You can usually tell when it starts to kick as it start to thicken ever so slightly. If you wait until the color starts to change you probably waited too long.

[2850Bounty]

Wayne, I agree.

Greg, just so you know what's being discussed here... the resin/catylist mixing ratio will include a temperature scale. But you probably know that.

[Guest]

I used a heat light on mine but I was just sealing the edges of a new hole I cut for a volvo setup that had been merc.

I let the heat light warm up the area for a few hours, then applied the resin and which I had kep inside overnight, left the light in place. It was slower than the time on the can but it did cure. I then followed up with a couple coats of sherwin williams marine enamel over the glass just for the extra protection. Killed me to lose almost a week waiting for everything to dry good in the mouldy PNW but it came out good.

[Guest]

I don't see a temperature scale on the can. It just says to use if over 65 degrees. If it's colder you can double up on the hardener. :-)

I may pick up some of the IR lights and cover my engine bay. A lot of my work can be done in my garage before I actually get the pieces in the boat.

Just as an update, I couldn't find fir plugged 3/4" anywhere. The best lumber yard in the area said he stopped selling 3/4" fir 5 or 6 years ago. I told him what I was doing and he recommended a product called Advantech. I didn't get it but it seemed like a good concept. It's a fiber based OSB. He said that he left a jobsite for 4 months uncovered. He said that none of the pieces were effected by the weather. He said any other plywood would have been junk. The advantech uses fibers and epoxy. There are reports on line of leaving a sheet floating in a lake for a month and the wood was still perfectly in tact not effected byt the water.

Two things help me back although he said not an issue to the first. I thought that because it was OSB it might not hold screws too well. The second was I didn't know if the OSB would effect the box beam effect. I thought that since it wan't layered like plywood it might.

I opted for AC plywood with exterior glue. I've cut it to fit, rounded the edges and sanded it. I'm ready for poly, maybe sunday.

Oh, I beveled the bottom edge to conform to the hull angle. I then rounded the edges. Will this be a problem with the glass?

Greg

[boatworkfl]

yachtman wrote:
You can heat it with lights but it really should be closer to 65-70. If you catylize it too much you can also change the properties of the resin and it wont be as strong. I would wait. I am having the same problem chomping at the bit to work on it but the temps arent just there yet. Small areas would be fine as they can be heated. Large areas are a different story. The night tem shouldnt make a difference as it should already be cured in a half hours time. If not its too cold.

You couod tarp it and use a propane heater or such. Be careful if you have flamables around. Me persoally i would wait. Oh yeah im already waiting

Propane is not good, water is the byproduct of burning propane, water will nutralize the catalyst on the surface....