Heat Delima - Ideas?

Need some advice from some fellow handy paddlers. I live in upper midwest, my workshop is in an unheated garage. Most projects I just layer up, get to working and the cold doesn’t bother me. This winter I have a couple of boat related shop projects that I’m really juiced up about, but the cold temps are holding me back from glassing and gluing.

Been looking at electric heaters, Kerosine, wood burners. Any affordable suggestions? Am I missing an option (aside from building a new garage). Garage is not insulated, it’s a garage and a half, so not too big. My fear is if I invest in some heat, I still won’t have the temps to cure adhesives properly. Wife won’t let me clear out the dining room table to work inside…ha!



I use an electric space heater
I have the hull supported on stands with nylon straps and just place the space heater underneath the boat. If the boat is suspended inverted the warm air gets trapped underneath the hull pretty effectively. If you do this monitor the hull for the first hour or so to make sure you are not going to melt it.

Use halogen lights
for spot heating. Use regular heaters to get the overall temps up and then point a halogen light at the specific area on the boat. I think I heard about doing this from the West System Epoxy folks, but can’t remember.

Well, I would do the following -

-since your stand up paddle board is not that big, I would hang a tarp over it, and stick a blowing-type-electric-heater underneath. I am quite sure that would raise the temperature a bit. Blowing type - to distribute heat more evenly.

-if tarp were unavailable, some poly from home improvement stores would work. Or those emergency mylar blankets, they might be better since they do reflect heat.

Think positive - since it is cool you have extra time to work with glues and epoxies.

That board looks very promising - are going to fill it with low density expanding foam and glass over?

LP gas space heater …

– Last Updated: Feb-06-13 10:58 AM EST –

....... 30,000 btu with oxygen depletion safty cut-off sensor , automatic thermostat control or 5 heat levels , automatic electronic pilot (usually battery operated) ... should be enough to get her warmed up . Some models have a fan ...

Do you have open rafters or flat cieling ?

Nephew uses two 20 lb. LP bottles , has them valved at a T , left on or right on . It's easier to deal with two 20 lb. bottles and they are more readily available at many local places for swap out than a single 40 lb. bottle .

Follow up.

– Last Updated: Feb-06-13 2:16 PM EST –

I was thinking more towards kerosine. I'm not an electrician with the amps/watts side of things. Garage is tied to the house, so I don't want to trip a breaker every time my wife uses the toaster. Right now I have to be careful if we have a space heater and then run the vaccum. Just need to be careful where we plug in.

With kerosine, it eliminates electricity. Just not sure if I can raise 20 degree temps to high 50's/60 to get stuff to cure properly. Still not sure I can glass properly at those temps. Even with electric, I might be able to get it comfortable, but not proper temps. I did some experiments without heat and everyting just gets brittle.

Suriam, yes You saw my FB post. The plan is to foam the rails with good old fashioned home depot 2" insulation which I'll layer to the right thickness and fit in 12" lengths between the ribs. I have a deck and hull that will be recessed along the ribs and then glass the whole thing after shaping rails, sanding, painting, etc. The hard work (measuring and frame cutting) is done, now it's just like a big tinker toy that needs to be assembled with adhesives.


I also have thought about tarping off the project site with tarps or visqueen, but worred about unattended heat sources overnight.

You are right about making sure you’re not melting the boat. In late fall when temps were iffy, I was heating a small repair on a thermoform boat with a basis shop lamp. Thought the head from the bulb would give me just what I needed for some sustained heat. The edge of my work lamp was too close to the deck and I melted a dime size divot near the day hatch. Oops. Might have caused the hatch rim to sag a bit, but it’s not realiy noticable.

I saw DIY surfboard thermocure project were a guy built a heat box out of 1inch rigid insulation. I can’t recall details, but he was happy with results. He was able to get temperatures high enough for his purposes, that will definitely be enough just to get epoxy set.

(polystyrene melts at 460F)

Comment on Kerosene

– Last Updated: Feb-06-13 1:20 PM EST –

You will have no trouble finding a kerosene heater that can keep the place toasty warm, but not all models and styles will do the trick. I once had a blower model (the kind with a tubular shape that sounds like a tiny jet engine) which I think was rated for 150,000 or 175,000 BTU, and it would get a 4-car garage (no insulation and open attic space) up to 70 degrees in a very short time on a cold winter day. I'd end up running it for 15 to 20 minutes at a time, with the "off" periods being a lot longer than the "on" periods. You can get thermostats to regulate how they turn on an off, but I just did it manually. I could have used a much smaller unit and it would have done the trick, but while running a larger proportion of the time. In your situation, a blower-style heater of much smaller capacity (75,000 BTU?) would probably be plenty. I have never heard any positive comments about non-blower styles of kerosene heaters except when used in very small enclosures, but someone else may say otherwise.

The PROBLEM you may find with a kerosene heater that's big enough to keep the space warm, is that the exhaust is unpleasant over extended time periods, and anything in the garage that is cold becomes a condensation surface for all the water vapor that's in the exhaust (the windows will be constantly dripping, and all your metal tools in the building will be soaking wet until such time as they become about as warm as the heated air, and that takes a long time). You might also want to research whether any of your adhesives or resins cure improperly in the presence of combustion by-products. If the heater is small enough that the exhaust presents no problems at all, it probably won't produce enough heat to make the garage very warm.

I used that big kerosene heater for a few years but eventually got sick of dealing with combustion exhaust and installed a vented natural-gas heater. However, for short work periods I didn't mind kerosene fumes too much.

I remember being in my grandfather’s old shop during the winter and he used kerosene and I don’t really remember the fumes or condensation on tools? He used a couple of those upright kerosene heaters to warm up the shop while he worked. Visqueen drapes to section off parts of the shop he wasant using.

I don’t think he had ones with blowers, but I do remember fans moving the air around? I’ll have to do some more reserach. Not sure how to figure BTU’s vs the amount of space I need to warm. I bet I can it warm enough for most adhesives, but not fiberglass until maybe early spring.

I had very bad results doing this …
I did a project on my unheated patio here a couple of years ago. Usually not a problem in Southern California, but we had a big temperature drop, and I tried using spot lights keep the epoxy warm. Problem was it created hot zones very near the lights and cold zones quite close by. I probably could have worked out a better system but was not impressed with the results I got trying this once. I have seen surfboard makers who have a huge insulated box, and a conveyor, and temperature regulators with a big array of lights but it probably is not easy or cheap to do this.

COLD- If the reaction quenches
you have a F…ing mess that oozes hardener …

Also be careful of fumes under tarps etc. The chemicals in epoxy are nothing to fool around with breathing.

The smaller the heater, the less exhaust
… and the less exhaust, the less water vapor you’ll have. I had a pretty big heater, and when used a lot, there’d be plenty of condensation on everything that was cold metal or cold glass. When I was a little kid my dad heated a 2+ car garage with a very small style of blower heater, and I don’t recall condensation issues, but the place never got very warm either, maybe 40 degrees was the best it would do in cold weather. That’s why I think a heater that’s too small to cause issues with exhaust fumes or moisture condensation might be too small to provide a truly “warm” work environment, but I’m just “putting two and two together” on that score based on the little bit I’ve seen.

Wife might leave town with the kids for the weekend. I might do the dining room table afterall? Seriously. have tarps, will travel right? Nobody tell her! Glue residue in the air only lasts so long, right?

No smell
Use good boat building epoxy and you will have almost no odor (System 3, MAS, etc.).

Good luck! Alan

Project priority
Just got through a stretch of sub-zero temps here. Days at or below 20. I kept my shop in the mid 50’s with a propane “Big Buddy” catalytic heater.

But my garage is insulated and drywalled. It wasn’t always. I decided a long time ago that it wasn’t practical to heat an uninsulated shop in those kinds of temps. Besides the cost and the fumes, there is the increased fire hazard.

Maybe you should consider a different winter project - insulating that garage. It’s one of the cheaper home improvement projects, and pretty easy too. Makes a huge difference in the quality and amount of winter “shop-time” you can have. Even with temps hovering around zero, I never see the garage thermometer go below about 35. Doesn’t take too long to get it up to 50, and I can hold it there with the heater on a lower setting. I don’t have condensation problems.

and a good carbon monoxide detector

Yes, that.
And check the gas connections before every use.

propane , LP gas …

– Last Updated: Feb-08-13 12:25 AM EST –

...... any potential for LP gas (propane) burners , appliances , etc. to emmit carbon dioxide in levels that are above the safe levels , is due to the unit burning extremely inefficiently due to lack of proper oxygen levels being available to the combustion mixture .

Also improper gas pressure to the appliance can be the cause of this . To much pressure and to much gas is released at the combustion point , and not enough oxygen to support burning that much gas ... the result , inefficient gas burn (incomplete gas burn) ... the exhaust has to high of concentrations of , CO2 - NO2 - CO - water vapor .

This can be caused by fouled orfices . Fouled orfices (fouled with carbon build up) that happened because there was not enough oxygen in the combustion mix .

The way it can happen that there becomes not enough oxygen is that the oxygen in the closed area that the unit is burning in has become depleated because the burning unit has used it up already . Therefore , it is important to be certain there is sufficient "fresh air" allowed into the closed burning area (ie, a vent to outside or cracked open window , etc.) .

This is why they tell you to not use your gas range as a heater inside your home . The assumption is that if using the range as a heater , you will be doing so for long periods of time such as full or part days , many hours in a closed space (the home) . This has the ability to use up the available oxygen and thus causing the range to burn terribly inefficiently , which in turn can cause the carbon build up on orfices , and combustion exhust byproduct to emmit higher than safe levels of carbon monoxide .

The same would hold true with an LP gas space heater . Therefore it is recommended that if one choses an "unvented" LP heater , one should be certain an "Oxygen Depletion Sensor" (ODS) "safty cut off" feature is part of the heaters make up .

When it comes to the carbon monoxide issue of the various fuel types of available space heaters that are not "externally" fresh air vented nor chimney exhausted ... LP gas is the safest by far .

The water or condensation issue from burning fossil fuels is due to the byproduct of burning hydrogen ... ie, water . In dry winter air , sometimes the added moisture into the air can be a benifit . If the space the heater is heating already has high humidity levels then the result will most likely be condensation on things .

The most important thing to remember when using a non vented space heater , natural gas , LP gas , kerosene , other ... is be certain you have a fresh air exchange taking place in the area the heater is heating .

And in all cases it is recommended to have a carbon monoxide (CO) alert sensor installed in the operating area ... just be safe .

Hard-wire one of these in:


I use a pair of the 900 watt versions in my 24x30 garage and its more than adequate. They are inexpensive to buy and operate.

No affiliation with the manufacturer, just satisfied product user.