@Laszlo [Quote]Don't you live in sunny, warm Greece?[/quote]
Close! I live in SW Turkey where we never see snow but temperatures can fluctuate quite a bit. It was 26°C yesterday but that dropped to around 10°C during the night. In the summer months temperatures can be 40°C + and 30°C overnight. Winters are fairly wet with torrential rain but also periods of beautiful, warm weather with low humidity. Variable I suppose you could say. With such variations I don't worry too much about ideal temperatures for working with epoxy, if you've got it to do, then you have to do it whatever the conditions.
Below is a photograph of a thermometer sitting on the hull of my (at the time) unfinished Skerry, It's outside my house as I don't have a garage or workshop so I have to work with any temperature fluctuations rather than try and control them. I'm not alone in this either, all around the world people make boats working away in different situations and different conditions and doing it successfully so while the original question is worthy, to me it's all a bit academic as basically you've got to work with what you've got.
I read on another forum that painting a boat black in a mediterranean setting would make it fall apart as the ambient summer temperature would soften the epoxy enough to make it fail. My Ches 17LT is black with epoxy/graphite on the bottom and they're wrong. It's fine.
That's 50*F by our scale! I'd dearly LOVE it were our winters that mild. Was -10*C here yesterday when I got up, we can expect -26*C - or worse - in a few weeks.
I'm contemplating building a roofed deck alongside my garage if & when I get wind of CLC moving forward on their expedition canoe design, some place I can work outside in the shade yet be able to cover the sides during our spring & fall when it gets kinda dampish & I need supplmental heat.
I'm in NE Florida. Two nights ago we woke up in the camp ground to 29 degrees F, sunny Florda can be cool too.
.
Welders here often use a plywood box here with a light bulb inside to keep open welding rod cans/rods warm and dry. We often just made 3/4" ply boxes and sometimes insulated them when available. The 3/4" ply was just the most available excess available when the welders showed up.
.
If you were to "tent" the boat and keep a lamp in there to warm it there is such a thing as fire treated/resistive visqueen. Contractors making temporary (very temporary) dust partitions in hospitals and computor facilities often use it. In any event you'd keep plenty of air gap around the boat, lamp, tent, etc. I don't tent the boat but focus my quartz work lights mounted on tripod stand on the affected area. I need the light to see anyway.
.
I've also used Christmas lights, before LED, around wells and pipes to keep them warm. They could be used in the box.
Spclark, you live in Turkey, that's very interesting. Love me some Hatsan Air guns!! I really wish our lows were only 10C or 50F. Last night we were -.5C or 31F we often hit -23C or -10F in the winter around here. It has been an abnormally warm fall for us, but the cold is coming!
No, I'm in US of A, state of Wisconsin, more specifically an area known as the Driftless Region (east of Mississippi River from north of La Crosse south into Illinois; never saw the last glacier) just south of La Crosse. Also referred to by the locals as God's Country.
You, being in Turkey, could say much the same though as Mount Arrarat is there I believe?
Being recently married myself, I appreciate the tenuous position you're in. Might I suggest that any savings on the heat bill will be more than eclipsed by expensive failures of plywood, epoxy and skilled labor?
I'm the one that lives in Turkey Mike, a village just south of Marmaris. I have two Hatsan air rifles and they're pretty good for the money!
@spclark
Mt Ararat is indeed in NW Turkey - I climbed it in June 2015. I'd post a picture of the summit but visibilty was about 5 0r 6 metres, the wind was howling and the temp was about -30°C. There are no traces of an ark although the locals will sell you a bit of wood if you're interested. :)
So what is the consensus? How low can the tempersture be and the epoxy still kick? I have one I am needing to glass the hull on but the garage is running around 60 but dips to 50 at night. The oil burner that heats the house is in the garage but the metal garage door is not insulated so I lose a lot of heat.
I have been proceeding like I said in the 1st post. I let the temp drop to 50 when I am not working. I raise it to about 65 when I am working. Now just to make it a bit more complex I do leave it at 60 when Epoxy is curing. I have had no trouble at all.
I also have had no problem working with temps in the 60s and letting things cure overnight in the 50s. In those conditions, I find that warming my resin/hardener by putting the jugs in a sink filled with hot water makes it easier to work with. The only exception is that I want the garage much warmer when wetting out glass. Epoxy gets very viscous when trying to wet out glass on a cool surface. I will not glass unless I can get the garage above 75.
My only large-surfaces experience with epoxy has been with WEST System products. They have different hardeners to use depending on cure temps anticipated though in reality it's the high end - working at elevated temps, making pot life shorter - that dictates whether a change in hardener is required. Here's a link to a page showing which hardener might best be used for a given temp range.
Were I messing with MAS products for the first time I'd try to maintain at least 50*F in the immediate environment of the work I'd be doing over the 24 - 36 hours I'd expect to be needed for 90% cure to be achieved. This can be done efficiently in otherwise unheated spaces by careful use of incandescent light bulbs and fairly close-set polyethylene sheeting to keep the air warmed by the light(s) as clise as possible to the curing epoxy.
I did forget to mention, at least an hour before I plan on working, I turn on a work light and point it directly at my epoxy jugs. This warms them nicely and I have had no problems with viscosity.
I rigged up a thermostat to a outlet to run my kerosene torpedo heater. You want to use the cheapest "baseboard heat" thermostat that uses a bi-metallic element and directly switches 120/240 volts -- I found mine at Lowe's for $20. DON'T get the programmable fancy-dan one, those are for regular furnaces and A/C and operate at the millivolt level, not what we're looking for.
I used two junction boxes screwed to a 2x4; one for the thermostat and one for the outlet.
You just plug in the device to be controlled, -- electric heater, whatever - and then set the temp. Rig it so that when power comes on it supplies heat -- set to to max temp or whatever, to "bypass" the device's internal thermostat should it have one. I like the external thermostat because I can put it wherever I want, I have mine at "head height" ; not on the floor where the heater sits.
I use a small temp data logger I bought on Amazon for $15 that plugs into a USB on a computer. It logs the temp once a minute (or whatever interval you set it to). Handy to know what your heating system is doing.
Kerosene Torpedo heater? I have one of these. It is as loud as a jet engine and stinks to high heaven. Now mine is from the 80's so maybe they have improved them?
Oh yes, it is loud! It really kicks out the heat though. Mine does not stink (much) and burns very clean. It runs for about 2-3 minutes about 3 times an hour at 45F outside temp to maintain 70-75 in the shop. It'll be interesting to see how much it has to run later this week when the outside temps drop to 25F. I suspect supplementing the torpedo with the 1500 watt electric convection heater will reduce the amount the torpedo needs to run quite a bit. I see the torpedo heater as the "bulk heat" source.
If available space and your work flow permit, 'tent' your project off with poly sheeting (heavier the better to keep it from getting blown around by drafts). Put the electric heater inside that, with your project, while also striving to make the tent as leak-proof as is practical.
Put the kerosene heater outside the tent, where your heat loss thru exterior walls is greatest, and maybe you can sleep at night (NOT WITH THOSE HEATERS RUNNING!) free of worries about epoxy contamination from combustion byproducts.
All good points, fortunately the shop is a detached garage thus no CO worries in the house.
Tenting and shop lights may work but it's a bit more difficult given the project: it's the teardrop camper. Tenting a kayak or some such sounds easier! :)
Concur about trying to find an alternative to the kerosene torpedo heater, for lots of reasons. I have a propane fired unit Amazoning it's way to me now actually.
I do in fact have a CO meter / alarm in the shop, no issues there so far! While insulated there are vents in the door. Great points though.
The instructions in the kit with the MAS epoxies say: "store ... at room temperature. Do not allow to sit on cement floor. ... Dispensing resin and hardener above 60F is recommended", and according to CLC's documentation for the NED, curing should happen at 70F for 24 hours before moving parts.
