Heat question - Hammerite paint

[Greylag]

Hello All,

Well after pricing up chroming and powder coating I've decided being a cheapskate I'll paint the rocker box top covers myself I'm thinking of using Hammerite smooth which will stand temperatures to 150 centigrade (300F) and hopefully give me a nice heavy coat of paint

What I need to know is do the rocker covers reach that sort of temperatures? I would think not but I'm not sure so would appreciate it if someone could enlighten me as to whether the Hammerite smooth paint will be suitable for the job?

Regards
Dave

[Ken Hanna]

Dave,
you might be safer using one of those VHT paints, which are supposed to be OK up to 650*C, as long as you don't mind a matt finish.

Mind you, it depends on the state of tune of your engine and how hard you work it...
http://www.youtube.com/watch?feature=pl ... yy-g#t=94s

Ken

[Greylag]

Thanks for the reply Ken,

I won't be using it hard, both it and me are plodders . I've had it flat out at 65mph and that was only once, I usually stick to around 50-55mph. I'd prefer a gloss finish if I could get one but if not it will have to be matt. I'll swap them my engine for that one, mind it looks like they've used either powder coating or paint on the rocker covers

Regards
Dave

[Paul Narramore]

Powder coating isn't expensive if you shop around. I've just had a motorcycle frame, centre stand, coil spring and a few bits & bobs done for £75, a lovely finish and suitable for your rocker box covers. Do make sure the object is zinc primered first as many don't do this, only for the glossy finish to fail after a few years.

[Paul]

Hi Greylag,

My air-cooled 500cc parallel twin motorcycle engine reaches about 175 deg C at the spark plug when ridden hard. The reading is taken from a Vector Trail Tech speedometer that has a heat sensor sandwiched between the spark plug and the cylinder head. With moderate riding, the temperature is usually abround 145 deg C. All figures are from memory (mine, not the speedometer's).

As there is a gasket between the rocker covers and the heads, the rocker covers' temperatures will be well below 175 deg C. I'd give the Hammerite a go first; it'll only cost a few pounds and some time.

Regards
Paul

[david]

I have used canister spray paint [red] to do matching wheels and rocker covers..That stands the test of time...

[hutchii]

Dave, If you're right that Hammerite will withstand temperatures to 150 deg C you should be pretty safe. I just looked in the Car builder Solutions catalogue, the Durite gauge they sell peaks at 150 Degs. Presumably Durite have a good idea how hot oil gets?
In a post on the old forum about oil temp, and where to measure it, if I remember correctly, Ken Hanna suggested the rocker cover. Given the amount of oil that remains in there due to the height of the push rod tubes, that will be the test of the temperature spec of the paint!

[Greylag]

Thanks All for the replies.

According to their bumpf it will withstand temperatures to 150 degrees Hutchii but I'm going to get VHT silver paint and see what that comes out like. If it gets damaged the good side is that it can be recoated.

Powder coating is good but I've been informed that if it gets damaged ie chipped the rot sets in which you can't just redo cheaply. Now all I need is some decent weather to spray the rest I want to spray and job's a good un as they say in Yorkie land.

Thanks again all
Regards
Dave

[Ken Hanna]

Dave,
domestic management went out in her Dyane today (weekly run to Rawdon to check how #1 grandchild is doing ) so when she arrived home I checked the rocker cover temperatures using an infrared thermometer.

87*C on one side, 85*C on the other, if that's of any help...

Ken

[Greylag]

Hello Ken,

Thanks a lot. Based on the manufacturers bumpf (150c) and your findings it looks like I may be able to used the Hammerite after all, that's plenty of leeway according to their specs. I like the idea of the Hammerite as I can brush a good thick coat on them then rub them down and spray the top coat on. I want to use the Smooth stuff on the skirt and back crash bars anyway as they get a lot of hammer with grit and muck from the wheels.

Correction : Just had another look at the spec sheet guess it won't be suitable after all.

Limits: Minus 20ºC (-4ºF) to 150ºC (300ºF) maximum intermittent when fully cured. Continuous 80ºC (180ºF) when fully cured.
Note: Colours may fade after prolonged exposure at temperatures exceeding 50ºC (120ºF).

Thanks anyway Ken
Regards
Dave