- A brush paints an engine well. Thick enamels level themselves, and a bare block on a stand takes a brush better than a can mists it.
- Of these six, only POR-15 and Jenolite publish coverage figures.
- The ratings run from 150°C to 650°C. Only one tin here is for anything near an exhaust, and it is not an engine enamel.
- Thin with the maker's thinner at the maker's ratio, or not at all.
- Price per 100 ml is shown on the day from Amazon's figure; the tins look dear until the sizes are compared.
Why a tin
Aerosols are quick and the makers' sheets are written for them, but a brush has three things going for it on an engine. It wastes nothing into the air, which matters when the colour is a marque shade that costs what Frost's tins cost. It reaches the places a spray mists past, between the pushrod tubes and behind the water pump. And the thick enamels made for it level themselves: POR-15's is about 80% solids, and its instructions say the brush marks flow out as it dries.
The other reason is colour. Most of the marque colours on the OEM colour reference are sold in tins, not cans. Applying engine enamel covers the brush as well as the aerosol, and the spray gun guide says what it takes to put a tin through a gun.
Reading the ratings
POR-15 rates its Engine Enamel to 300°F, about 150°C. Frost gives 170°C for its tins. Eastwood gives 650°F, about 343°C, for its ceramic enamel and says in the same breath that it is not for manifolds. Jenolite gives 650°C for a paint that is sold for stoves, and E-TECH and Fascinating Finishes give no figure we have found.
For a block on a road engine, 150°C is enough and the finish and the colour decide. For an alloy head, or an engine that is worked, Eastwood's margin is worth the size of the tin. For a heat shield or a bracket by the manifold, only the Jenolite is rated for it, and a manifold itself takes a very high temperature coating, by brush if you want: POR-15's High Temp is one.
A missing figure is not a low one or a high one. It is a reason to keep that tin on the block and its covers and nowhere hotter.
Brush, roller or gun
Stir a tin, do not shake it. Work from the top of the engine down so that runs get picked up as you go. Thin coats, and the second when the first is dry to the touch: POR-15 says within 24 hours, with no drag under a finger.
Every tin here can be sprayed, with the maker's thinner. Frost says up to 10% white spirit. POR-15 says up to 5% of its own reducer and nothing else. Eastwood says brush or spray without a ratio on the listing. Jenolite says brush, roller or gun. Thin an enamel with the wrong solvent and it can curdle in the cup or dry with no gloss, which is in the common failures of the spray gun guide for a reason.
Coverage
Two of the six say how far a tin goes. POR-15 says a pint does a whole engine. Jenolite says 15 m² per litre. Eastwood, Frost, Fascinating Finishes and E-TECH publish no figure, so size is the only guide: a quart or a 500 ml tin for a block, 250 ml for a cover.
Divide the price by the millilitres before you compare. The table shows the figure per 100 ml from Amazon's price on the day.
What to check before you buy
The colour, from the reference, and whether the tin you want is listed on your engine's record.
The part, against the rating: block and covers for the four enamels, shields and brackets for the Jenolite, nothing on a manifold from any of them.
How long you have. POR-15 wants four to six days before the engine runs; the others give drying times rather than schedules.
Then the price per 100 ml.