Forum bmwbike.com

I have a problem on spray paint at my R 26 cylinder.
I paint it with high temp spray paint after a couple of weeks the paint become crack off.
If any one have some suggestion for this problem it will be very kind of you.
THANKS very much indeed
LAND OF SMILE

Paint works best if there is no old paint or rust on the cylinders, and if the new paint is not applied too thickly.
In my three restorations, the cylinders were bead blasted clean and then spray painted. The spray does not reach into the fins very well, so I applied the paint to the sides of the fins with a Q-tip (cotton swab). To obtain liquid paint, I sprayed paint from the can into its top.

Thanks Allan,I'll try.It's the last thing I'm gona do to my R 26 restoration.

If you do bead blast, here are some things to consider --
Cover the top and bottom of the cylinder with duct tape so the abrasive media cannot enter the barrel. After the bead blasting, wash the cylinder inside and out using soap, brush and hot water (to heat the cylinder for faster drying), and rinse with a strong spray of water. Then use compressed air to blow the oil passages out, and to dry the fins. The clean bare iron will rust very quickly, so immediately apply a very thin coating of oil inside the cylinder barrel, using your finger to rub it around. Do not get any oil on the outside or the paint won't adhere. Then cover the top of the cylinder with masking tape cut to fit the gasket surface, and cover the bottom of the cylinder also, and cover the chrome pushrod tubes. Then paint the exterior of cylinder as soon as possible, as it will also begin to rust.

We have been powder coating our cylinders since more than 20 years. We find that it is the only reliable heat resistant coating that lasts forever.