DIY Powdercoat Oven - Val6 Diesel heater?

[martyy]

I am just starting to look into powder coating and have decided that I will likely be building my own oven to try and keeps costs down. Probably going to be 4' wide X 6' tall or close to that size. I have seen various threads on using Mr. Heater propane heaters but I have a Val6 MPX diesel heater rated at 60k btu and was thinking it might be up to the task. The MPX is awesome and puts out a ton of heat. It does have a fan but works as infrared heat, so it does not blow crazy like those propane heaters. With it running you can have a conversation with someone right next to it. Seem like it would provide an even temp if I can get it to seal up around the edges of the heater. Any of you guys out there with more experience have thoughts on this being a worthwhile endeavor (as far as the MPX as the heat source)?

Link to heater
https://val6heating.com/models/mpx/

-Marty

mpx_main.png

[DieselFumes]

I am not sure that would get it hot enough and unsure if any exhaust fumes would affect the finish. I would just go electric. Can pick up old oven burners super cheap or free and just wire them up.

[acourtjester]

This is what I use plus an oven element or two easy with no fuel to add.
https://www.ebay.com/itm/234591957598?h ... R_qvzLnLYQ

[martyy]

I am not sure that would get it hot enough and unsure if any exhaust fumes would affect the finish. I would just go electric. Can pick up old oven burners super cheap or free and just wire them up.

I think it will get plenty hot as I just ran some tests with the infrared thermometer. I set a piece of mild steel 2ft from the face of the heater and within 3 minutes it was almost 300 degrees with temps on the face of the heater over 900 degrees. The exhaust fumes are surprisingly low, well maybe it shouldn't be a surprise at the cost of these Val6 heaters. They are touted as extremely clean burning. Other than repurposing an existing item, one of the reasons that interests me is the speed in which a heater like this would get things up to temp. I am checking to see if there are any ovens on CL or FB. I have not even got a gun yet. Thanks for chiming in.

[martyy]

This is what I use plus an oven element or two easy with no fuel to add.
https://www.ebay.com/itm/234591957598?h ... R_qvzLnLYQ

That is dirt cheap.

[34by151]

You need a pid controller regardless of the heater type

[martyy]

You need a pid controller regardless of the heater type

Yeah, i am looking at the one acourtjester posted. The Val6 already runs off of a simple manual thermostat which calls for heat. The Val6 heater is different than the propane torpedo style as it has a fan cool down period. I don't need the PID to control the load for the heater, rather just a dry contact to control the call for heat. Hope that makes sense.

[34by151]

I started with electric.
The issue with this is massive amount of power needed and the slow reaction times

I upgraded to a turbo type heater (50kw LPG) but replaced it with a Riello Diesel 2 stage heater (240Kw)

A turbo style is an open loop heater. This means it relays on air flowing though the heater
The only change is toy need a bigger exhaust port. If the port is too small the oven is effectively blocking the heater and it will either shutdown or burn up.

When I had the turbo hater my oven had 2 x 65mm exhaust ports at the bottom
After changing to the 2 stage heater the ports were reduced t 2 x 12mm
The 2 stage is a heat exchanger, heat is transferred to the second stage. This second stage draws in air from the oven heats it and pumps it back.
In other words its closed loop

You wont have any issues with the burner and surface finish in fact its better as your are forcing the fumes from the powedercoat out the exhaust port.

Its important for the parts to get to temp as quickly as possible
Most powders begin to flow at 170c but need to get to 204c to start the bake cycle
The time to get from 170 to 204 is important to the quality, the faster the better
I'm refer here to the temp of the parts not the oven
The more parts you have and the ticker the metal the slower it will heat
The only option is more power. More heating in KW
How you heat it , electric, gas, diesel is not important just how fast it heats and how stable the temp is

My oven internals are 2.4m high x 1.5m wide x 1.2m deep
I can fill the oven with the 10mm thick parts and it will get from 170 to 240 in under 2 minutes
With a couple of 2mm signs that would be seconds

Why do I have diesel 2 stage
Its cheep to run, far cheaper than electric and about half LPG
Im limited to 64 amps per phase, 3 x 64amp @ 220V, roughly 35Kw

The small LPG heaters are in the 20-50Kw range
My Diesel heater is 240KW so in electric that would be 400amps 3 phase or 1200 amps single phase

[34by151]

The pid just monitors the oven. Its connected to a contactor or ssr that turns the power on/off for the heater.

The val6 will still not like a closed oven.
That's like blocking the heater, it will shutdown
The exhaust port needs to be a size that allows the heater to run without shutting down

All ovens need a vent anyway to rid if the powder fumes and allow for heat expansion

The specs say it needs a 110cfm air flow
Just pot in a big port with a flap that can be adjusted
When you test the oven have the port open. Keep testing till you find out how much you can close the port and not have the heater shutdown.
As you reduce the port the heating time will get quicker as well

[martyy]

The pid just monitors the oven. Its connected to a contactor or ssr that turns the power on/off for the heater.

The val6 will still not like a closed oven.
That's like blocking the heater, it will shutdown
The exhaust port needs to be a size that allows the heater to run without shutting down

All ovens need a vent anyway to rid if the powder fumes and allow for heat expansion

The specs say it needs a 110cfm air flow
Just pot in a big port with a flap that can be adjusted
When you test the oven have the port open. Keep testing till you find out how much you can close the port and not have the heater shutdown.
As you reduce the port the heating time will get quicker as well

Tons of good info in your posts. Thank you.