Ski Builders Forum

I need hotbox to accelerate cute of topcoat. No room for storage of properly billed insulated box. The only thing I can come up with is a retrofit press and use top blanket for heating.

Anybody build one? Some advise… Ideas would be nice

Just build one out of solid insulation that you can take apart - I've seen them held together with bungee cords, they do the job and are not a permanent fixture in the workshop

I build a temporary hot box around my longboard press by using sheets of 2 cm Polystyrene foam insulation.
I tack it together with long nails or a bunch of pieces of wire or welding wire which I use as Pins.
Duct tape doesn't work as the heat softens the glue too much.
Nice and cheap, and quick to put up, take down. Storage is easy too as all the sheets are flat.

third, I use the one inch thick pink rigid insulation panels from Home depot, but use 3 inch wood screws they pull the pieces together snug, hold pretty well and you can lift the box off and put it over your working surface. I just made the sides and a top piece. I just let the lid sit on top with some things to hold it down snug.

this route I don't want to take need something different. Have no room to store box (even if it taken apart).
if to put together sections of the box plus heating lamps chicken coop style not to mention temperature controller it's a lot space which I don't have.

Pink insulation board is combustible and will burn also splash of acetone will melt it. Yellow insulation board with foil faced much better approach as far tape
3 inch foil tape will do the job.
But this is not the route I want to take

btw what heating elements you guys using?

It's pretty much the best option tbh, you don't even need to build a frame for it - I've seen 50mm thick celotex (polyurathane solid insulation) just placed around the object, bungee chord around the whole lot and the lid placed on top. no need to seal the edges at all

Heating element, anything from a 100W light bulb to a 3kw cooker element (depending on size of the box and temp required etc.

If you want a quick and dirty fix then get some chicken wire / welded mesh bend into a hoop long and wide enough to cover your part, add heating element (light bulb) and cover with reflective foil (like you get when you run a marathon) - it will reflect the heat back and keep it in the space you've made but you'd have to test out to see what temp it can maintain.

When it comes down to it, if you want a heat box it's going to take up some space no matter what!!

I disagree. it can be done not quick and dirty using combustible materials but properly and silicon heat blankets can do the trick.
My problem is I may or may not use this topcoat in the future and different one most likely not need hot box.

for now I going test to see how 1 blanket from the press will work

Do you intend on doing a topcoat of epoxy with mylar/release film then?

I read (maybe wrongly by the sound of it) that you wanted to apply a clear coat topcoat (like durepox / spray clearcoat) hence my suggestion to use an air based heat chamber.

If you intend on using a heat blanket applied directly to the board/ski then theoretically as long as you don't exceed your original cure temp then it "should" work

My system is very basic.
Like I say, I build a polystyrene box with an opening at one end just big enough for a fan heater, and a gap at the other end for the air to come out. Takes 5 minutes to set up / take down.. cheap as...
However It is probably not the safest thing in the world.

How hot do you want the box to get? Are you trying to speed up post cure? If so, try using a blanket with a space heater. I will usually cover my press with a tarp and place a space heater under the tarp and warm everything up and do them same to the skis after pressing.

skidesmond wrote:How hot do you want the box to get? Are you trying to speed up post cure? If so, try using a blanket with a space heater. I will usually cover my press with a tarp and place a space heater under the tarp and warm everything up and do them same to the skis after pressing.

not really hot maybe 100-110F to speed up drying of topcoat because it self leveling. But before going hot box direction will try different topcoat first which not self leveling

I had conversation with someone very knowledgeable on the subject of drying clear top coat.
Two part PU or epoxy if dried too fast can trap moisture inside. When dried appeared glaze or cloudy on the surface which not easy to get read of afterwards. So to my understanding accelerated drying can create big problems by itself. for this method to work need control environment.

Regular exterior poly dries fairly slow, levels out nice though, but the fumes can be a problem if not well vented. Dust is the enemy of poly and epoxy top coats because of the long drying time. I've used 2 part poly and it dries rather quick, no obnoxious fumes, but doesn't level out quite as good as exterior oil based poly.

If you stick with exterior oil based poly it's probably more important to have a clean room or cover it. If you're doing it in a cold garage/basement then you probably want some level of heat, at least room temp, 65F.

at this point I decided to go clean room direction even it sound complicated but so far it more reliable and consistent. btw fast drying or accelerated drying approach also need clean room anyway plus controlled environment for humidity that in my situation difficult to achieve

Done some test already and happy with results. My PU need 6 to 8 hours to dry to touch

I used a hot box for a 2 component clear coat, and it developed bubbles. A right p.i.t.a. Couldn't get rid of them. Ruined a good project.