Cylinder Black

Hi Keith. I personally use Smoothrite, (smooth Hammerite). It comes in spray cans so you can get to the bottom of the fins, itinhibits rust and lasts forever.

Hope this helps

Emlyn

Previously keith_owen wrote:

Hi,

Can anyone recommend a cylinder paint with which to black my cylinders / does anyone know what commando barrels were originally painted with?

Have used Granville but it doesn't seem to last.

Thanks, and BR,

Keith

Hello Forget Granville and forget hammarite You need VHT FIRECOAT Black Gloss Very Hight Temperature paint up to 550 F clean all fins well first and sprayon then let dry and then place in the oven for 15 minutes too hardened this makes a top job yours Annaj

Previously keith_owen wrote:

Hi,

Can anyone recommend a cylinder paint with which to black my cylinders / does anyone know what commando barrels were originally painted with?

Have used Granville but it doesn't seem to last.

Thanks, and BR,

Keith

Hello Forget Granville and forget hammarite You need VHT FIRECOAT Black Gloss Very Hight Temperature paint up to 550 F clean all fins well first and sprayon then let dry and then place in the oven for 15 minutes too hardened this makes a top job yours Annaj

NORTON OWNERS CLUB STILL Has a TECHNICAL ISSUES WITH THIS WEBSITE Please try and rectify them YOURS AJD

Originally the barrels would have been stove enamelled. I had mine powder coated black years ago then had them done silver to return it to standard (1970 750) this stayed soft when heated in use, I then oversprayed that with PJ1 which has become available again after disappearing for a few years. It's a good finish, nice and shiny, it will bake itself on in use so don't stink your kitchen out with the barrel in the oven trick when the missus is out, but do put the barrels in the dishwasher before painting. don't then hang about getting some oil on the bore & tappet tunnels and other none painted surfaces.

Jim Comstock did some trials with various coatings including black, silver, powder coating and bare metal. the difference in heat dispersal was negligible.

Have to agree with AJD VHT Firecoat

I use satin black spray, as used on woodburning stoves.

Each to their own but the best I have with the neatest finish is powder coat. A good coater will use a much thinner coat on barrels than on frame and tinware.

There is an opinion amongst some racers that powder coat on barrel fins reduces their ability to cool engines. Just sayin!

Also some BBQ/stove paints are oil/ petrol soluable even when dry. Ok if your engine doesn't leak/carb drip!

There is an opinion amongst some racers that powder coat on barrel fins reduces their ability to cool engines. Just sayin!

Also some BBQ/stove paints are oil/ petrol soluable even when dry. Ok if your engine doesn't leak/carb drip!

Smoothrite seems to be OK to me. Best brushed on if you can to get a decent thickness of paint and 2 coats. The big advantage is that my local hardware store stocks it.

The heat radiated from the barrel fins is related to the surface emissivity. The shinier the surface the lower the emissivity. For example, polished aluminium has an emissivity of around 0.04 whilst oxidised cast iron is around 0.64, some 16 times greater. This would seem to indicate that a dull finish will radiate heat better than a smooth/polished finish.

There is an opinion amongst some racers that powder coat on barrel fins reduces their ability to cool engines. Just sayin!

The Jim Comstock experiments David Evans refers to confirms this opinion is unfounded, they are on youtube and worth looking at if you still have any doubts.

Matt black is best for radiating heat. Have a read of black body radiation if you want further detail. However, in the real world, matt black coatings do tend to be porous and of no great strength. So a ride in the rain, not uncommon in these parts, has consequences. I go for a strong and mostly decorative glass black finish which can withstand normal usage.

My pre-WW1 Douglas has bare cast iron cylinder/heads and minimal finning and gets treated to a tube of stove black polish and a toothbrush annually. Works fine but not really durable.

Previously john_holmes wrote:

The Jim Comstock experiments David Evans refers to confirms this opinion is unfounded, they are on youtube and worth looking at if you still have any doubts.

If thats the case then thats obviously fine but personally I wouldn't powder coat anyway, it's difficult to touch up and will lift if the surface is at all rusty. PJ1 silk black works fine for me, but might try Anna's suggestion. To be honest a too black and shiny barrel looks out of place to me, I don't ever remember cast barrels staying clean and black for long! But each to their own, the biggest issue with modern rattle cans is their lack of resistance to petrol.

Previously Dan Field wrote:

Previously john_holmes wrote:

The Jim Comstock experiments David Evans refers to confirms this opinion is unfounded, they are on youtube and worth looking at if you still have any doubts.

If thats the case then thats obviously fine but personally I wouldn't powder coat anyway, it's difficult to touch up and will lift if the surface is at all rusty. PJ1 silk black works fine for me, but might try Anna's suggestion. To be honest a too black and shiny barrel looks out of place to me, I don't ever remember cast barrels staying clean and black for long! But each to their own, the biggest issue with modern rattle cans is their lack of resistance to petrol.

Hello I have used Anti-ethanol Lacquer from a so-calledrattle can with pull ring topressurise on the underside it's very good stuff see my Manxman tank and my barrel have a nice black shine has its black high coat gloss and heat resistant up to 550F and anti-ethanol anti-oil of any kind and hard to chip off find something that can match this has I have triedand tested all products to destruction , believe me, Yours Anna JAttachments
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Anna, we always believe you.

Anna it's not the ethanol, it's the petrol, my EO had the same effect. but what lacquer did you use, Halfords petrol resistant lacquer is rubbish!

Anna it's not the ethanol, it's the petrol, my EO had the same effect. but what lacquer did you use, Halfords petrol resistant lacquer is rubbish!

Hey Dan, there's an echo in here.................

Previously Dan Field wrote:

Anna it's not the ethanol, it's the petrol, my EO had the same effect. but what lacquer did you use, Halfords petrol resistant lacquer is rubbish!

Hello Dan The one I used Did Not Come from Halfords I use Nu-again Paints of Bedford See his web page you may find him better on eBay HUGSPAINTS yours, Anna J

Previously Chris Grimmett wrote:

Stefan's Law. Black body radiation is a 4th power law related to temperature (in Kelvin, naturally). The site limitations on typefaces preclude a proper exposition of the equation. I'm sure Prevost's Law of Exchanges comes into it somewhere as well ....

Yes, paint your barrels matt black. PJ1 was the product but it suffered at the hands of the VOC regulations. I have a can of the reformulated version but have not tried it.

There are very few 4th power laws in existence. Another one that affects us however is the deterioration of road surfaces relative to axle loading. That's why when HGVs went from 38 tonnes to 44 tonnes the effect was not 1.16x worse, but 1.80x. This explains how we now have deeper tramlines cut into the inside lanes of our motorways.

Hello Chirs Nice to know you are fit and well and still have time for bit of fun on this website Yours Anna J

Chris: I'm impressed! All that schooling was good for something afterall!