Fluoropolymer non-stick coatings

1. Coating composition resisting sloughing from a non-horizontal metal substrate prior to baking, comprising

(a) an aqueous medium,

(b) melt-fabricable PFA perfluoropolymer dispersed in said aqueous medium and having a melting temperature of at least 290° C., and a sloughing-resistant amount of the combination of

(c) melt-fabricable FEP perfluoropolymer dispersed in said aqueous medium and having a melting temperature of no greater than 270° C., and

(d) water miscible organic liquid having a boiling temperature of at least 280° C., wherein said sloughing-resistant amount is either from 1 to 8 wt % of (c) and from 0.5 to 3 wt % of (d), or is no more than 3 wt % of (c) and no more than 2 wt % of (d), all based on the sum of (a), (b), (c) and (d).

2. The coating composition of claim 1 wherein the sum of said (c) and (d) are present in at least 3 wt % based on the sum of (a), (b), (c) and (d).

3. The coating composition of claim 1 further comprising filler (e) for increasing the impermeability of said coating composition.

4. The coating composition of claim 1 further comprising no greater than 5 wt % of heat resistant polymer binder, whereby said non-horizontal surface requires a primer layer for adhering said coating composition to said substrate.

5. The coating composition of claim 1 wherein said both said perfluoropolymer (b) and said perfluoropolymer (c) are powder.