Greetings fellow nerds.
In a previous video i asked for help in repairing my hotplate stirrers.
I received a huge number of suggestions and offers and I'd like to thank you for helping me out.
First, an engineer generously fixed my old IKA hotplate.
The particular problem was beyond my ability to fix but i'm glad it was within theirs.
If you're watching thanks a lot.
Now my other two hotplates had burned out mica heating elements.
In my old videos i asked for suggestions on how to replace them, if there were companies that could make them,
or if anyone was willing to go in with me to group buy them.
I received a huge number of suggestions and I was given a company in china that could make
the mica heating elements for much cheaper and in smaller quantities than the one i originally found.
Instead of paying $3000 for 100 units I was quoted $500 for 30 and that is just within my ability to buy on my own.
So I did and here they are.
Now i know i could have bought a whole new hotplate stirrer for that price and i may indeed do so in the future.
But i really wanted to fix my two existing ones and having spare elements means
i can be certain i'll always be able to fix them many times over.
The certainty of being able to have two more working hotplates when i need them for years to come
is slightly more valuable to me than having one new hotplate of uncertain lifetime and repairability.
Especially since having two means one can be in service and one can be a backup.
But i'm getting ahead of myself.
Let's get these installed and tested.
Interestingly enough these holes match up perfectly with the elements they are replacing.
Either the crude measuring picture i sent them of my burnt element was enough for perfect duplication,
or this particular size and hole placement is pretty common
and the company had the tooling and assembly line already on hand.
Considering how willing they were to sell me just 30 units,
which is well below the minimum order quantity of other companies, I think it's the latter.
First i'm going to repair the cheaper sci-basics brand hotplate.
All i really gotta do is remove the old burned out heater element and replace it with the new element.
The thermometer insulation has cracked and peeled off so i'm insulating that with a mica sheet.
I'm actually somewhat impressed with the quality of lead wires of the new elements.
They took the time to insulate them, and use quality connectors.
They could have saved a few cents and not bother
but the fact they did raises my hope a bit that the nichrome foil element itself is a bit better engineered than my previous elements.
Only time will tell but score one for this chinese manufacturer.
And there we go.
This is heating up quite quickly.
It works! Interestingly enough you can see the hot plate smoking.
Don't be alarmed.
This is normal for a brand new element being turning on.
The resins, machine oils and adhesives used during manufacture are burning off.
After several minutes of high heat the plate will stop smoking and be ready for use.
Obviously do this part in a fume hood.
Anyway, I now have another hotplate stirrer back in service.
Let me go to the next one.
This ISG brand hot plate that is actually a rebranded dragon labs or scilogex hotplate.
Let me take it apart.
You know, while i'm here and have the hotplate top disassembled.
I might as well clean and resurface this thing.
It's been through hell and i won't get another opportunity like this for awhile.
First i'm going to grind off the residues with steel wool.
To help it along, i'm going to use some oxalic acid and hydrochloric acid.
Now i'm moving aside the hot plate unit and laying down some foil.
Here is our chemically cleaned, ground and washed hotplate top thoroughly dried.
Now it just looks like it's been through war and not hell.
To resurface this is pretty easy.
We spray on this high temperature enamel paint.
Usually you apply two coats but I don't need my plate looking new, i just need it to look less like a methlab auction sale.
Most labs don't bother restoring the coating at all since it reduces thermal transfer ever so slightly.
I wouldn't bother either but this hotplate is essentially on display in my videos.
I'm might as well make some effort to make it look good.
Anyway let me leave it overnight to dry.
And here we are.
A resurfaced hotplate top.
Okay let's get back to installing the new element.
Now, I'm not certain how long these elements will last in the long term,
but you know what, let's make an experiment out of that question.
In one year remind me to make another video commenting of the reliability of these elements in that year.
Now I had a lot of suggestions for building a hotplate from scratch.
I do intend to do that someday but i needed working hotplates as soon as possible.
I had many suggestions to build my own heater element using nichrome wire and i tried, but i failed every time.
The wires kept flexing and moving out of place and then shorting out.
I didn't have the mechanical skill to do it.
I'm not saying it can't be done or even that it's hard.
I'm just that bad that i couldn't make a wire element myself and had to get these elements manufactured.
If you can build your own wire elements then by all means do that.
Anyway, a fully refurbished hotplate.
Let me test it out.
And it's working too.
Looks like i'm back in business.
Time to start on some real chemistry again.
Thanks again my viewers for helping me out.
One of you outright fixed my IKA hotplate.
And some others found a manufacturer for the heating elements of these other plates.
I went from zero to three functioning hotplates and couldn't have done it without your help.
Thanks.
Special thank you to all of my supporters on patreon for making these science videos possible
with their donations and their direction.
If you are not currently a patron, but like to support the continued production of science videos like this one,
then check out my patreon page here or in the video description.
I really appreciate any and all support.