[angippp]

here are my plans for building a DIY flash dryer from a halogen cooker and a tin cooking pan.

1 remove bottom cover to expose screw posts, the original idea was to remove the glass cover entirely, but once i got inside you needed to remove another 2 layers of metal and unhook the heating element to get it off so I left it on.

2. on the cooking pan draw round the metal guard and make markers where to drill holes for the screws, i made tabs as i wanted to keep as much metal away from the halogen bulb as possible

3. drill holes for screws and a hole in the center to allow me to get the tin snipes in

4 cut away excess metal to leave just the tabs with screw holes

5 place tin baking pan between the base and the lower metal guard and screw in place using the metal tabs. because the glass curves away from the heating unit i had to replace the original screws with longer ones of the same diameter.

not tested it yet but i have an infrared thermometer gun and will do so after i get my work area sorted. Whole process took less than 30 mins.

photos can be found here

https://drive.google.com/folderview?id=0BxncQEV9qEFoYVB0Z0lTUEZtMm8&usp=sharing

 

[OneTrickPony]

Will be following your tests

 

[angippp]

not tried it with ink yet but with just a shirt it hit 330 at 1 min 30


folder edited to show it in operation, thats ladies tank top to give an idea of size the 364 is what it hit at 1.30 mins after it had warmed up

 

[msiok]

Keep us posted on your testing. This is really interesting

 

[angippp]

Keep us posted on your testing. This is really interesting

ok this is just a test print with a screen i have laying around, i normally print transfers then cure them to the shirt with a heat press, so this is why the print is in reverse, and a bit thin as its supposed to be distressed.

I allowed the cooker 1 min to heat heat up then placed over the print
( this is only half of the design there is supposed to be the band name above it but im pretty sure it would all have fit under the unit, ill check with my largest designs if it covers the whole surface and get back to you )

after 30 seconds the ink in the center of the print was smoking but the outer edges were still tacky.

after one min the outer edges were dry to the touch and no ink was transferring to my hand when i pressed on the print.

laser reading was around 208, I think ive read somewhere that the flash temp for plastisol is 210 as the reading on my gun drops rapidly as soon as the unit is moved that sounds about right to me. either way the ink was touch dry.

Photos updated with test pics

As all I wanted to do with this unit is to flash so I can do 2 colour printing im very happy with the results so far. and im pretty sure it will cure the ink completely.

I wont bother testing it with this screen as its very thin ink deposit wont give an accurate reading, will update when i get round to it.
https://drive.google.com/file/d/0BxncQEV9qEFoUi1KUldlQTZyUG8/edit?usp=sharing



Total cost if buying the cooker new around £25 - cost of purchasing a flash dryer in the UK £300+

 

[angippp]

update:
Ive had a think and i think that putting the metal guard back in its original position is making the air vent to close to the shirt, so ive modified it by fliping the guard over and adding a couple of nuts to the screws to keep the guard away from the heating element, this allows for a better coverage of hot are as it now escapes higher up in the cooker tray and so can circulate better.


this does seem to work as there is now far more smoke escaping from the unit in a far shorter time, and the center of the area hit 355f in just over 1.30 this only allowing the element 30 seconds to heat up.

photos added to show mod

 

[angippp]

I think the next mod will be a circle of tin attached to the inside of the original metal guard,
The theory being that at the moment the heat is being forced down before being drawn back in at the top by the fan, there by over heating the area directly below the heating element,

I think if i add a circle of tin raised on bolts to give space for the hot air to re enter what will now be a heating chamber . hot air will be forced out wards into the curing chamber before being sucked back in under the heating elements so giving a better heat distribution over the whole surface of the shirt.

 

[BroJames]

we call that a turbo broiler. What I did was put the cooker on a wire rack (instead of a tin). I covered the open spaces above with fabric as it was "experimental". I did not "perfected" it as I've not been screen printing much since. I've shifted to a heat press as I've been doing more heat transfers but I'd get back to this cooker if I need to speed up production.

This in an earlier picture with makeshift "throw pillow" sides. I later covered the sides with aluminum foil, insulation, and then fiber cement boards with 2 or 3 holes about 1/4" in diameter on all 4 sides(can't remember the number of holes).

 

[angippp]

ok thanks my idea behind the tin was to contain the heat as much as possible, my thoughts were circulating heat would reach a higher temperature faster- I want to move the element higher to get a more even coverage so i may try lifting it on a wire rack. where did you put your holes?

 

[angippp]

ok cool, i think i have a basket that hight, ill give that a shot too.
thanks

 

[BroJames]

My ultimate aim was to make drawer type curing box but I never got that far. Essentially, you pull out the drawer, lay the shirt in, close the drawer and cure the shirt for "n" seconds.

Let us know how things turn out.

 

[angippp]

yeah i had a similar thought maybe using a metal tool case, but i dont have access to that kind of cutting equipment

 

[angippp]

ok mod added and a definite improvement, temp between what was under the bulb and the outside of the shirt was over 100, i added the aluminium meat tray with fins to direct the heat out towards the sides of the pan ... the difference in temp was around 50degrees, turning them in towards the center and the difference has dropped down to 10 with the center under the aluminum being the lower temp, so the addition of some holes in the aluminum should result in an even temp all over

 

[thievecollective]

we call that a turbo broiler. What I did was put the cooker on a wire rack (instead of a tin). I covered the open spaces above with fabric as it was "experimental". I did not "perfected" it as I've not been screen printing much since. I've shifted to a heat press as I've been doing more heat transfers but I'd get back to this cooker if I need to speed up production.

This in an earlier picture with makeshift "throw pillow" sides. I later covered the sides with aluminum foil, insulation, and then fiber cement boards with 2 or 3 holes about 1/4" in diameter on all 4 sides(can't remember the number of holes).

I like the ingenuity bro jakes. What's the max size print that bad boy will cure?

 

[2020 PrintWorks]

I've been meaning to take pics of mine. I picked one up a few weeks ago from Goodwill for about 5 bucks. I attached a tin pan to the bottom of it. The kind you would use for a turkey. I'm actually using it to flash and cure. Once the pallet heats up it will cure in about a minute thirty. So far I've done around 150 shirts with it. All full size prints(11 x 11). It's definitely not ideal but for the money I don't think you can beat it.

 

[2020 PrintWorks]

we call that a turbo broiler. What I did was put the cooker on a wire rack (instead of a tin). I covered the open spaces above with fabric as it was "experimental". I did not "perfected" it as I've not been screen printing much since. I've shifted to a heat press as I've been doing more heat transfers but I'd get back to this cooker if I need to speed up production.

This in an earlier picture with makeshift "throw pillow" sides. I later covered the sides with aluminum foil, insulation, and then fiber cement boards with 2 or 3 holes about 1/4" in diameter on all 4 sides(can't remember the number of holes).

I don't know if it will get hot enough this way. With mine, like I said, I have the baking pan attached to it and I took a 1/4 piece of plywood that I cut a hole in 12" x 12". I lay that on the shirt so that the design shows through and then put the cooker directly on it. Putting the cooker directly on the shirt without the wood was leaving impressions.