Andrew R Stewart 

I am about to rattle can a new build (wide tired path drop bar bike). Here in the Rust Belt tomorrow's high of about 45*F will be not what the paint wants. I have a few ideas to deal with this while spraying. (Warm up frame and paint cans before, after use heat gun to try to keep applied paint sort of warm and know that set up time will be much longer). This paint job will be a short term one. I fully expect to want to modify the frame after some use and want the paint to be able to strip off easily in that future. I know some here will poo poo rattle cans or painting in too cold conditions but I am Ok with these for this job.

The reason why I post here is to see if others have made paint curing devices. I have a little experience with temporary home contraptions, now i am considering a somewhat more permanent solution. I have a low wattage industrial heat gun (hand held in front of nozzle for a minute at 6" doesn't burn me) for a heat source. Various materials come to mind for the enclosure, like Coroplast or plywood. Various ways to suspend the frame/fork inside the enclosure have also been thought about.

I would love to see some real world solutions. perhaps I will have a device when it comes time to clear coat over decals in a few weeks. Andy

fishboat

Using rattle can paint at less than 60-65 degrees will certainly be easy to strip. Hopefully the paint will setup to tack-free at some point (not a sure thing in my mind). The last bike I painted (last summer) must have had rattle can paint. I applied chem stripper to it and had the frame down to bare steel and ready for re-paint prep in about 15 minutes. The bike I stripped and painted previous to that (Lemond Poprad) had OEM paint and clearcoat on it. Using a chem strip, razor blade, emery cloth approach on that one took 14 hours to get to bare steel.

That said..if I were to attempt this while keeping the cost low and easy to do(if you prefer rigid walls)..I'd use 4x8 rigid foam board(exterior house sheathing) and halogen shop lights. The foam board is easy to cut with a bread knife or razor knife and be hobbled together with duct or gorilla tape. Foam board will keep the heat in. The older halogen shop lights kick out PLENTY of heat and light..you'll need both. I'd think a couple/few of the old-style halogen lights could be had on CL. Newer shoplights will be LED..lots of light, but no heat. If you or the bike frame(or foam board) is too close to the halogen light it'll be too hot for you or paint or board. I'd think a halogen light will soften/burn foam board. Burned foam board can give off poisonous fumes..be careful. Halogen lights and no walls at all might be warm enough for basic painting. They kick out a lot of heat. They also draw a lot of power..you'd kick a panel circuit breaker if you plug too many into the same circuit.

unterhausen

It should work to heat the frame and paint and then put it in a heated box immediately afterward. We have a couple of oil-filled radiator heaters that seem like they would work okay for inside the box. The box would be a convenient way of pre-heating everything.

Tandem Tom

Maybe Doug Fatticwill weight in!

Doug Fattic 

Herbie Helm came up with a simple solution. He found a used metal clothes hanging cabinet. At the bottom placed he a self contained home fryer made for making pancakes or similar. On the side he drilled a small hole where he could insert some kind of food thermometer. It warms up the box to about 125 degrees which is about perfect for baking off epoxy type paint. At that temperature it takes about an hour to bake off.

Another method I’ve heard about is to build a box similar in shape to a bike or frame box. It could be made out of almost any type of material. Make it tall enough to put some baffles at the bottom to keep hot air from a commercial heat gun (similar to a hair dryer) from blowing directly on the frame itself. Of course to top would have to have some kind of vent for the flow of air from the bottom to go out of the box.

Andrew R Stewart 

All these ideas I have thought about with no direction yet decided. One issue is space, the wife doesn't need more stuff to remind me of So a box I can break down is what I am thinking. I have halogen work lights I could use, they do throw off a bunch of heat. But they would need more space and separation from the box structure for safety. The use of a foam board also concerns me somewhat but I have done worst things before

When I was at Cyclery North we painted with Imron and had a scrapped metal cabinet (twin doors and tall like a coffin on its end) as our baking box. IIRC there was a radiant heater's element sitting on the bottom. That cabinet got pretty hot but as I didn't do the painting I didn't pay too much attention. It took some careful positioning to not have a frame touch the cabinet's interior.

Doug's comments about how much heat is needed is one I believe too. We (Doug has helped me paint a few frames at his shop) have talked about a baking box before. Both times it was warm weather and we used mu car's interior as the box, sitting in his yard in the sun. The way i see it for my down low painting goal any temp above the ambient is good. I have found out that too much heat can cause off gassing issues when there's multiple layers of paint or decals (bubbles developing). Thus my idea of using my heat gun as it's not too hot for my skin.

Today I sand blasted the frame/fork (the bulk of the tube surfaces were already sanded) then sprayed the primer with less than great results. The primer solids flowed away from edges and quite a few runs happened. Now, about 8 hours later, the primer is still tacky but slowly turning dull as it off gasses. I did the frame/fork warming best I could and the rattle can was very warm when I started. No surprises here. I will let the primer fully harden (will take inside the house in a day or so after the bulk of stink is past) as I pursue the box idea. At least now the steel is coated and I can easily sand smooth the primer before returning to recoating. I'll follow up here as I figure this out. Andy

base2 

I wonder if running a dryers exhaust hose or a hose from the discharge side of a canister vacuum to a cabinet would get you the warm air needed. As to how free of particulates that air would be is anybody's guess.

How much is a sheet of blue insulation foam from the hardware store, a fan & a radiant electric heater from the local thrift store? A probed kitchen thermometer ought to be accurate enough, I should think.

Another thought is a few 100 watt bulbs and a 4 or 6 inch air circulating fan in a plywood box a lá baby chicken hatching style.

Building the box into the corner of your garage already has 2 walls & the floor (or ceiling) taken care of.

Kontact 

Reflective backed Styrofoam board in an A frame over several incandescent flood lights?

Andrew R Stewart 

Here's today's efforts. Lots of hand cutting/filing, sanding and $120+ at Home Depot. The box is very rough and has lots of gaps to vent



off the hot air. The heat gun is a 5 amp/120V rated for 200*-300* (600 watts?). Moderate temp output compared to others I have used for other work, IMO. Still the box gained 40* above the basement temp, 64* to 105*. I ran this for about 30 minutes with no issues WRT the Coropast walls and the heat. The "door' wasn't held tight against the vertical PVC pipes. The wood top has a gap equal to the joints' walls all around the top edge. I think I can improve the sealing in a number of areas and have a slightly higher temp.

One aspect of this box is that I can break it down, or so I have tried to plan for. Only the top PVC loop is glued, the uprights are a slight taper fit top and bottom. Nearly 40 zip ties.

Sorry about the bland photos. Lots of white on white. I was able to dab some primer (filling pocks) on this frame as part of the box's test. It off gassed far quicker with the box's warmth, than the other day in the cold garage. Andy

unterhausen

That looks nice. The big box hardware stores have aluminum hvac duct tape that should work well to seal that.
You can also use it on your guitar if it has problems with electrical interference

Doug Fattic 

Nice work Andy! For those looking for a commercial product that works perfectly for curing frame paint, google “warming ovens”. They also are listed under the name holding or proofing ovens (for making bread). I got one for our church many years ago. They are often used for potlucks. Members bring dishes already cooked from home before church service and keep them warm in one of these ovens until after church is over ready to serve. Going by memory the one our church has is a Crest-X brand. Restaurants and other food preparation services obviously use them too.

They stand about 6’ tall and maybe 30 inches deep. The width and depth is designed for some standard size aluminum trays used in the food industry. The one we use is not insulated and made out of corrugated aluminum. There is a temperature control at the bottom as well as a timer switch. They provide heat up to almost 200º F. A heat chimney in the back brings forced hot air up from the heating unit with slits along its length to distribute the heated air evenly throughout the camber.

New they cost between $1,000 and $3,000. There must be used ones available somewhere for a lot less. What I learned from our warming oven is that the unit does not need to be insulated nor sealed.

Andrew R Stewart 

I added a few slight improvements today. First was to reduce the frame's twisting about as it hangs from the hook. It took a few minutes of playing with stuff for that light bulb to go off. This hook with prongs works rather well.



Next was the lack of best wall/door sealing. Two cheap lashing straps drew the door down much tighter than before.



Last up was the large gap around the heat gun outlet. Even though the heat gun nozzle would stay quite cool (could hold it by hand while the gun was on) I took the precaution of allowing more coroplast gap. I cut a snug hole in a piece of wood and with it against the coroplast wall the gap is much less.



My test showed the warmth built up a bit faster and got another 5-10* higher. Now about a 50* increase the room temperature. I am now happy with this (except for the fork holder, that replacement is waiting for a 1 1/4" spade bit to drill a wood block and then screw the block to the wood base). Hopefully I'll have a chance to respray the frame with primer (after some sanding first) and see how a warm frame and warm rattle can work in a cold garage before I go to the Cabin Fever show in Lebanon, PA next weekend. Andy

Forgot to say that I added some foam insulating tape to the tops of the PVC pipe where the wood top touches it. You can sort of see it in the first photo. The grey layer.

Andrew R Stewart 

This is my last post on this, barring questions. I moved the box from the 65* basement to the 36* garage last night. Found a "ceramic heater" and tested it as a heat source. I could get the box up to 125* before i stopped it. Much higher a temp in a much colder location. Shows what watts can do, the heat gun puts out about 600 and the heater more than double that.

Today I reprimed the frame, off gassed it and started the color coats. The baking box worked really well to provide a warm frame to speat onto (the rattle cans had been warmed up in a hot water soak) and then to speed up the drying. Even with the high temp of the day having been in the mid 30*s the paint is now pretty firm with a few hours of baking.



I consider this box a success. After I apply decals and clear coat it will get broken down and stored for the next time. Andy