Page 1 of 1

Painting engine cases

Posted: Wed Sep 30, 2015 9:02 pm
by sydduckett
Im toying with the idea as the engines out for a rebuild over the winter. Iv been thinking of the pros and cons, i think i will have to do it with silent blocks in as i cant apply any heat to the casing after paint.
Thing is if they have to come out at some time in the future ill end up buggering the paint anyway. Thats the cons, the pros being its out, easy to do and i like the look.

Any thoughts on the above appreciated.

Ta
Sef

Re: Painting engine cases

Posted: Sat Oct 10, 2015 8:23 am
by kevspeed
Having the same thoughts myself.Ive had this stuff reccomended to me by a local feller who specialises in classic bikes.
He showed me a set of cases that were done over 10 years ago,and believe me,they still look good!!
Image 8-)

Re: Painting engine cases

Posted: Sat Oct 10, 2015 6:48 pm
by sydduckett
kevspeed wrote:Having the same thoughts myself.Ive had this stuff reccomended to me by a local feller who specialises in classic bikes.
He showed me a set of cases that were done over 10 years ago,and believe me,they still look good!!
Image 8-)
Im going for a candy but ta anyway

Re: Painting engine cases

Posted: Sat Oct 10, 2015 10:05 pm
by ricalnic
Personally, unless it's a show bike I'm not in favour of painted, or powder coated engine cases, IMO it's adding a thermal blanket to the motor, usually we would like means to dissipate heat and every opportunity to reduce running temps.

Re: Painting engine cases

Posted: Sun Oct 11, 2015 10:55 am
by ArmandTanzarian
ricalnic wrote:Personally, unless it's a show bike I'm not in favour of painted, or powder coated engine cases, IMO it's adding a thermal blanket to the motor, usually we would like means to dissipate heat and every opportunity to reduce running temps.
If I remember a school physics lesson from around 1980 correctly, doesn't black radiate heat more efficiently than bare metal? I vaguely recall a cube full of hot water painted a different colour on each side

Re: Painting engine cases

Posted: Sun Oct 11, 2015 11:51 am
by hungdog
ArmandTanzarian wrote:
ricalnic wrote:Personally, unless it's a show bike I'm not in favour of painted, or powder coated engine cases, IMO it's adding a thermal blanket to the motor, usually we would like means to dissipate heat and every opportunity to reduce running temps.
If I remember a school physics lesson from around 1980 correctly, doesn't black radiate heat more efficiently than bare metal? I vaguely recall a cube full of hot water painted a different colour on each side
So why are radiators painted white... :?: lol

Re: Painting engine cases

Posted: Sun Oct 11, 2015 6:44 pm
by hendy
ArmandTanzarian wrote:
ricalnic wrote:Personally, unless it's a show bike I'm not in favour of painted, or powder coated engine cases, IMO it's adding a thermal blanket to the motor, usually we would like means to dissipate heat and every opportunity to reduce running temps.
If I remember a school physics lesson from around 1980 correctly, doesn't black radiate heat more efficiently than bare metal? I vaguely recall a cube full of hot water painted a different colour on each side
You are 100% correct. It's called the emissivity factor. If something is matt black and everything within line of sight is cooler it will transfer heat into those bodies. Sounds like b@11@x, i know, but I've used this principle in my work for years and like all physics theories it's the same in real life as it is in the lab!

Sensible question about radiators, and the answer is twofold: first one is simple, black radiators would look s**t in your house; secondly radiators should really be called conductors as most of the heat transfer is by heating the air molecules that come into contact with them. In fact vehicle radiators work almost exclusively in this way.

Re: Painting engine cases

Posted: Sun Oct 11, 2015 8:49 pm
by coaster
kevspeed wrote:.............He showed me a set of cases that were done over 10 years ago,and believe me,they still look good!!
I used the very same stuff on a new SIL 200 casing and although it has held up fairly well, it has chipped and flaked off quite a bit and it's only been on 5 years. but it does get used all year round and has seen a lot of miles. I would think the cases you saw had had an easier time of it ;) That said, it went on very easily and is way better than standard satin black spray cans.