Heater (late square type) Overhaul

[Andmurph]

The motor label.

[svenedin]

When you fit the matrix you will see that the two spigots protrude through the case so that you can attach the rubber pipes. Use foam so that the matrix cannot move around and you can wrap the same foam around the spigots.

Stephen

[Andmurph]

Thanks Stephen.

I have the foam to wrap around. I was just wondering if a better seal could be achieved with grommets is addition. If you look closer at the side panel where the pipes protrude you’ll see the metal has rusted and the holes opened up slightly. These are earlier photos.
I will line the joins to the side panels with 1.5mm neoprene tape all the way around.

[svenedin]

The original way is a sort of foam washer around the pipe. You can see an old decayed one in the photo. If you do something similar, it will squash down on assembly and air will not be able to leak out of there. If using self adhesive foam, make circular washers and build up the required height.

Stephen

IMG_3529.jpeg (3.07 MiB) Viewed 1833 times

[Andmurph]

All stripped, cleaned and bathed in Evaporust for a few days then a coat of 2k primer. I think used a 2k epoxy filler to fill the worst of the rust pit damage before a further coat of 2k primer.

[Andmurph]

I had two 400ml aerosol cans of semi gloss black 2k paint mixed and set up a makeshift spray booth in the garage. The warm weather yesterday was ideal.

[Andmurph]

All painted and set to harden over the next few days in the back of my Volvo greenhouse.
I have a set of 20 (18 required) No.6 x 1/4 black A4 marine stainless steel screws ready to reassemble the case. I’m going to used neoprene for the seals on the motor with new grommets and bushes.

[don58van]

Stephen

Thank you for showing us your heater restoration project. Very impressive job.

I have a question: What crackle paint product did you use? Are there any tricks to get the paint to crackle properly that you can pass on to us? I have seen many reports of people unable to get a satisfactory finish.

Regards
Don

[svenedin]

Stephen

Thank you for showing us your heater restoration project. Very impressive job.

I have a question: What crackle paint product did you use? Are there any tricks to get the paint to crackle properly that you can pass on to us? I have seen many reports of people unable to get a satisfactory finish.

Regards
Don

Thank you.

Beginner's luck I think. I was very pleased with the crackle/crinkle/wrinkle on the front panel. I used VHT wrinkle finish over a good quality zinc primer (for rust resistance).

I looked at lots of Youtube videos and I was not confident about using a domestic oven not least because my kitchen oven is not very clean!

I sprayed on the wrinkle paint, not too thickly (you can always apply another coat) and then I used a heat gun. You need to keep the heat gun moving, and like magic the paint will start to wrinkle in front of your eyes. Be careful not to burn the paint as remember heat guns can be used to burn off and strip paint. I even saw videos where people wrinkled the paint by leaving panels in hot summer sun. If you mess it up then strip the paint off and start again. It is not a big deal really just for a small front panel.

I also wrinkle painted the motor housing on the wiper motor. This worked brilliantly as well but then the paint got damaged and I had to do it again. The next time the wrinkle just didn't work very well I think because I applied the paint too thickly.

Practice on some scrap metal first.

The lettering was done by a professional screen printer.

Good luck!

Stephen

[Andmurph]

Hi Don,

I too consulted Stephen and the YouTube videos and decided to go with a ready made facia from Nippycarsonline.com
They specialise in early Mini parts and make these on crinkle powder coat.
I did a pricing exercise on restoring my original vs ready made and it came out slightly in favour of ready made. My quality requirements often exceed my creative capabilities as well so it made sense to me. I am very impressed with the facia.

[svenedin]

I didn't know you could get them ready made! Looks great. If I did another I would go for the ready made


I found the link: https://nippycarsonline.com/product/heater-facia/

I used Nippycars years ago for very nice powder coated brackets for the fresh air ducting in the engine bay. They have some excellent obscure parts not stocked by the big suppliers.

Note Nippycars also sell heater "ears" but as far as I know, the Mini ears are not the same as Minor.

Stephen

[Andmurph]

You are correct Stephen.

The Mini ears they do are purchased from Minispares and then refinished. They are unfortunately different to the Morris Minor ones. Ive just purchased a second hand pair from EBay as the ones in the pickup were a good reclection of a heavily used commercial vehicle and beyond economic restoration.

I will try the traditional shoe polish approach when they arrive. I am going to try a plastic primer and 2k priimer on the old ones to see how it works with the rough finish. My guess is the paint will fill the texture.

The Nippy Cars website isn’t ecommerce ready but if you drop them a message via the Add To Enquiry Fred will get back to you quickly.
Fred regularly wins concours with his Minis and is well regarded in several Mini Facebook groups.

[svenedin]

You are correct Stephen.

The Mini ears they do are purchased from Minispares and then refinished. They are unfortunately different to the Morris Minor ones. Ive just purchased a second hand pair from EBay as the ones in the pickup were a good reclection of a heavily used commercial vehicle and beyond economic restoration.

I will try the traditional shoe polish approach when they arrive. I am going to try a plastic primer and 2k priimer on the old ones to see how it works with the rough finish. My guess is the paint will fill the texture.

The Nippy Cars website isn’t ecommerce ready but if you drop them a message via the Add To Enquiry Fred will get back to you quickly.
Fred regularly wins concours with his Minis and is well regarded in several Mini Facebook groups.

I'm sure you'll be very pleased with your heater.

One thing you might want to do before putting it back in the car is to test it on the bench with a battery. Even a PP9 has enough oomph to run the fan but a 12 volt battery is better. If you often refurbish car electrical parts (fuel pumps, horns etc etc) then a small lead-acid rechargeable 12 volt battery e.g burglar alarm battery is a useful thing to have. You can then test whether polarity makes a difference to which way the motor spins. If it does, it is a permanent magnet motor and it must be connected the right way for the centrifugal fan to deliver the best air flow. If it is a field coil motor it makes no difference and the fan spins the same way regardless of polarity (because both the armature field and the field coil field get reversed). From the outside these Smiths motor variants look identical.

With the ears it is sensible to try both techniques on different pairs of ears. If you use boot polish it will be very difficult to remove if you then decided to paint them. Waxes, silicones etc would be a nightmare to remove from textured plastic and would ruin any paint applied.

Stephen

[Andmurph]

Motor back together. I need to fit the new grommets and bushes tomorrow before riveting it back on. This one is a permanent magnet version. The serial number traces back to an MoD Lightweight Land Rover.
With new bushes and a thorough clean and grease it now runs strongly and is almost silent. It’s a shame I couldn’t remove all of the rust pits from the shaft without making it too narrow to re fit the fan.

[Andmurph]

New grommets and bushes fixed in with stainless rivets. I have a long handled rivet gun from my sailing days that I was grateful of.

New switch back where it should be. For many years it had a plastic switch mounted through the left heater ear. This was only possible as there were no lower footwell hoses attached.

I need to move the fan back up the motor shaft as I pushed it a bit too hard.

[Andmurph]

First test reassembly.
The foam on the flap catches slightly so needs shaving slightly. Otherwise I’m very happy with it.

The heater core was already upgraded and will go back in next week and I’ll tidy up the wiring.