Mini reflow oven advice And truth of T-962 having asbestos

Thread Starter

StealthRT

Joined Mar 20, 2009
274
Hey all I am venturing into making a DIY reflow oven. Been looking at many different types/styles over the last couple of years and feel now is a good time to start one.

I originally planned on building this type of toaster oven. Looked nice with a touch screen and all. It also didn’t use the stock heating elements. He used a circular halogen heating element. After talking with the guy he finally put his source code for it on his GitHub. I’ve watched his video over and over again so I could draw out the schematics and needed parts since he didn’t bother providing those in his GitHub.

I recently ran into a listing on Amazon for a mini toaster oven which looks like this:
CEFC5E8B-C5FC-450C-B124-1C60B7366790.jpegThe total watts is 550 and I know by research that it’s best to get an oven that’s between 1200-1500 Watts so this mini toaster oven falls pretty behind in that regards. However, those toaster ovens are twice the size of this mini toaster and I know the less area needing heated the less watts that would be needing. I would also consider getting one of those circular halogen to replace the top stock one in the mini - if it fits that is. Doing so would put it into that 1200-1500 watts that are suggested.

The size of the mini toaster is 8L x 6W x 7 inches height. Compared to a average cheap toaster oven measuring 15L x 10H x 11 inches height. They seem to go up to bigger sizes as the price gets more.

So, to those of you who have made their own toaster oven before - is this doable for unleaded solder with, of course, small pcbs?
 

DC_Kid

Joined Feb 25, 2008
924
You can always add another heating element or two. Your code/controller will need to be modified accordingly. Heating profiles and size of oven (and board parts) will dictate how much wattage is needed. Go with the smaller over, add an element or two to dbl the watts, code some profiles.
 

Ian0

Joined Aug 7, 2020
4,824
I made one out of a 2kW tabletop oven. I found that the rate of temperature increase perfectly fitted the profile specified in most datasheets. Make sure that your oven can get to 240°C - I think most of them can.
The important preheat is the preheat phase, without that it doesn't solder well.
I made a timer (just out of logic gates and counters) with a thermcouple and a triac.
Fix an old piece of pcb next to where you put the boards and attach the thermocouple to it to get a representative reading.
The result is ten times better than I Chinese soldering oven I bought off eBay.
 

DC_Kid

Joined Feb 25, 2008
924
Well, if it has anything bad in it, then don't buy it. Many many products have bad things in it. Teflon pans are very bad. China rules are a bit less than US rules, but bad stuff still sneaks in.
 

DC_Kid

Joined Feb 25, 2008
924
Only loose fiber asbestos is very dangerous. If it's captured (like in impregnated panel) then the concern is way lower.

Ask seller where it's used and if it's loose fiber.

Or, find another small oven.
 

Ajith-N

Joined Sep 14, 2020
16
Since you worry about asbestos, I assume you would want to do Pb-Free soldering as well. Results with this model are underwhelming, if you are expecting somewhat uniform results "across the board" (in both senses).
 

MisterBill2

Joined Jan 23, 2018
11,579
Asbestos is an effective heat resistant material, but it must be used properly. It is the dust, powdered form that is able to cause injury. So like many other materials one must understand what they are doing and take suitable actions to avoid injury.
Consider that even pure water can be deadly to the careless folks.
 
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