Thinking caps on everyone how can I make a DIY paint curing oven during lockdown

[AshimotoK0]

Well I saved our old kitchen oven at work for curing the paint on my 500 & 750 crankcases  .. for my  smaller engines we have big enough lab type ovens at work and I don't need to work on those yet anway. However, my old oven is at work and the premises are closed for at least another two weeks and I want to get my 500/4 engine put together during the lockdown period.

I have plenty of engineering bricks and wall coping stones plus I bought a NOS fan oven element off eBay yesterday .. only bidder .. won for £2 plus I have an industrial type hot air gun (designed for plastic welding etc). So thinking of trying to mock something up  outside once I have gone in my loft to see if I have some kind of thermostart / temperature controller. Thinking of using the hot air gun to provide air circulation.


If anyone has any 'make-do & mend' ideas, I am all ears. Using our new kitchen oven is out of the question, as my wife suffers from asthma so using that is definitely out of the question.

[mike the bike]

Sounds like you're on the right track with all that kit.
I would add a thermostat so your paintwork doesn't over heat and burn off.
Also I would angle the hot air gun past the fan element,  otherwise it will just glow red and burn out. Consider a vent as well,  you'll have air going in from the air gun, if there's no exhaust,  you won't get more air in and you'll overheat the air gun.

[Nurse Julie]

I could go to Tesco in Horncastle today, via Hull, bring everything back here and put it in our parts oven 😊😊👍

[AshimotoK0]

Sounds like you're on the right track with all that kit.
I would add a thermostat so your paintwork doesn't over heat and burn off.
Also I would angle the hot air gun past the fan element,  otherwise it will just glow red and burn out. Consider a vent as well,  you'll have air going in from the air gun, if there's no exhaust,  you won't get more air in and you'll overheat the air gun.

Yes agree . I ordered a 16 Amp capilliary type thermostat off eBay yesterday ... still polishing cases etc anyway so still not applied the paint yet. The oven electric element arrived too and it's 2.5kW so should provide a bit of heat in addition o the head gun.

[Rob62]

What about saving electricity and doing it on the cheap....just build a kiln with those bricks you have and build a little barbecue fire.... then when its glowing nicely pop your bits in there.... remove a couple of bricks if its too hot

[Seamus]

You could always use one (or more) old computer fan(s) to circulate the air in place of the hot air gun

[AshimotoK0]

Well here it is and I have baked the 500K0 bottom crankcase this morning. The top half is baking whilst I am typing this post.

I was initially going to sneak into work and, being an electronics engineer, I have loads of fancy pant's stuff at my disposal at work for controlling/monitoring temperature etc... but that's no use if anyone else wants to do the same as me ...  so I set myself a target to spend a tenner on eBay and buy domestic oven parts. I did OK.. I only broke the budget by £1.

I got an old computer fan as Seamus suggested to create airflow but in the end I decided that the crankcases are such are large thermal mass of alloy that it wasn't reallly necessary ... after all it's not a Mary Berry Victoria sponge I am baking 

I bought a capilliary type thermostat capable of switching 16A max and a cooker oven 2.5 kW element  all from eBay ..... all generic parts from standard domestic ovens (see pics.). I put the thermostats temperature sensing bulb inside the oil gallery of the crankcases in the 'oven'.

Like all good bakers I was up at the crack of dawn getting the oven on    Actually I did it early as the missus was in bed and the slightest whiff of solvent type paint fumes is bad for her asthma. In fact there was very little smell as there was a fair wind blowing but I have to be mega careful.

Good thing is, once I have finished baking all of my parts,  I can bung the bricks back behind the shed and the heating bits fit inside a shoebox for next time.

There is a great debate on all of the forums about the type of paint/baking the paint on crankcases for petrol resistance. Some bake, some don't. I don't really know if I am honest... I  just went with the type of paint and baking temperature that others have recommended on here and other forums.  It's one of those tasks that if you didn't do it you may have a nagging doubt. But if someone said b*llocks Ash .. I ride my bikes in anger and I will let the running engine temperature do the curing .. I wouldn't argue with them.


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[AshimotoK0]

I actual fact I did used to get up at the crack of dawn in the mid-70's baking bread, as every year, when I was a student, I worked on the ovens in a 'Wonderloaf' bread plant/bakery  in Hull. On my 1st day Richard Bean the now famous playwright started with me on the same shift on the bread ovens. On our 1st day there was an 'oven jam'. There was a conveyor oven that probably held about 1,000 loaves and one of us was accused of jamming it up caused by  a tin misplaced on one of the carousel shelves. Imagine 1,000 loaves all stuck in a non moving oven...disaster ! To this day we still argue which one of us was responsible for the jam. Richard went on to write his 1st play 'Toast' about our experiences in that bakery and is now a top playwrite having written 'One Man two Guvnors' etc.

https://www.youtube.com/watch?v=Ie_ZL2SHqFI

[Allington (Steve)]

Apart from tinkering with bits I can't do much to the 500 as I'm waiting for bits at the chrome platers. I think it could be some months...

[Oggie400F]

Looks good Ash.

Just a few of questions
Are they ordinary house bricks or oven bricks (is there a difference)?
Could you do a simple wiring diagram for us non-electrical engineer types?
How is the engine case supported, I assume not directly on top of the element?

This would be a good solution for myself, and many others I suspect, to prevent major upset with, and personal injury from, our wives or girlfriends or partners. 

Many thanks
Ian

EDIT:
I think I've answered two of my questions by looking more closely at the pictures.

House Bricks and Case is supported on the aluminium box section therefore will sit above the heating element.

[AshimotoK0]

Hi Ian ...  yea you sussed correctly .... house bricks .. sitting on aluminium extrusion (could use old oven wire shelf though)

Circuit as below

Someone mentioned element would burn out if not using fan...mine seems to have run for about 4 hours and OK without a fan  plus grill elements don't have fan, so maybe a grill element may be better if not using fan. Whatever ...  you need about 2.5 to 3kW (just capable of being run on a 13A socket). I just really used what I had. Top was a sheet of tiling cement board .. not asbestos based !

[ Guests cannot view attachments ]

WARNING !! if anyone builds a similar setup it's best to house the thermostat in a sealed plastic electrics box. Also if your house doesn't have an RCD earth leakage  breaker type fuse box (Consumer Unit)  then use an additional  plug type RCD for safety. Also connect and earth cable to to any metal parts.

[Oggie400F]

Hi Ian ...  yea you sussed correctly .... house bricks .. sitting on aluminium extrusion (could use old oven wire shelf though)

Circuit as below

Someone mentioned element would burn out if not using fan...mine seems to have run for about 4 hours and OK without a fan  plus grill elements don't have fan, so maybe a grill element may be better if not using fan. Whatever ...  you need about 2.5 to 3kW (just capable of being run on a 13A socket). I just really used what I had. Top was a sheet of tiling cement board .. not asbestos based !

(Attachment Link)


WARNING !! if anyone builds a similar setup it's best to house the thermostat in a sealed plastic electrics box. Also if your house doesn't have an RCD earth leakage  breaker type fuse box (Consumer Unit)  then use an additional  plug type RCD for safety. Also connect and earth cable to to any metal parts.

Thanks Ash

I'll order the element and thermostat and give it a whirl.
Can you send links to the items you bought please?

Also regarding the image, just to clarify, Is the Thermostat the thermostatic controller and is the Pilot Light the capillary bulb you placed in the oil gallery or am I completely wrong?

Ian

[AshimotoK0]

Hi Ian ...  yea you sussed correctly .... house bricks .. sitting on aluminium extrusion (could use old oven wire shelf though)

Circuit as below

Someone mentioned element would burn out if not using fan...mine seems to have run for about 4 hours and OK without a fan  plus grill elements don't have fan, so maybe a grill element may be better if not using fan. Whatever ...  you need about 2.5 to 3kW (just capable of being run on a 13A socket). I just really used what I had. Top was a sheet of tiling cement board .. not asbestos based !

(Attachment Link)


WARNING !! if anyone builds a similar setup it's best to house the thermostat in a sealed plastic electrics box. Also if your house doesn't have an RCD earth leakage  breaker type fuse box (Consumer Unit)  then use an additional  plug type RCD for safety. Also connect and earth cable to to any metal parts.

Thanks Ash

I'll order the element and thermostat and give it a whirl.
Can you send links to the items you bought please?

Also regarding the image, just to clarify, Is the Thermostat the thermostatic controller and is the Pilot Light the capillary bulb you placed in the oil gallery or am I completely wrong?

Ian

Capilliary bulb is part of the thermostat ..the pilot light is just a neon lamp to show you that the element is switched on or off and  not entirely necessary.

I got my heating element in an auction one off for £2 but this one is the same and up for an offer and there is also a link to my style of thermostat.

 ********   Please don't harm yourself !! ************

 https://www.ebay.co.uk/itm/Hotpoint-Oven-Heating-Element-2-5KW-Circular-C00199665-Ariston-Creda-Cannon/174238601028?hash=item28916e0f44:g:ASAAAOSws4NeheIA

https://www.ebay.co.uk/itm/Electric-Oven-Knob-Style-Thermostat-Disjunctor-Temperature-Control-Switch/164129581004?hash=item2636e2a7cc:m:mybV1kpohzZrT8d7qF_irvw

[Oggie400F]

Thanks for the clarification Ash.

Parts are on order.  I promise I will be careful and will not hold you or anyone else responsible for any outcome.

Believe me I would come to much more harm if I tried to use our kitchen oven again! 

[Oggie400F]

Thanks for the clarification Ash.

Parts are on order.  I promise I will be careful and will not hold you or anyone else responsible for any outcome.

Believe me I would come to much more harm if I tried to use our kitchen oven again! 

EDIT.
Everything ordered bar the cable to connect from my controller box to the heating element.
I assume that this cable needs to be heat resistant.  If so what spec do I need?

Cheers Ash. Hopefully this is the last question. 🤞