After coating a spigot wrap a few times i find it is very hard to get it flat i use heat but it still is very bumpy .should i sand it down before i recoat next time , if so how long do i leave the epoxy before it can be sanded .

Why do you use heat? Two things will really help - make sure the rod is level and don't put on so much finish. On longer areas, applying the finish in lengthwise strokes can make things a bit smoother.

You want to block sand the area to ensure that it really is flat. The finish must be cured sufficiently so that it sands rather than "rolls" off.

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It is bumpy ,will another coat help it or will the bumps always be there unless i sand it.

If the bumps are very noticeable, all the next application will do is just coat them evenly, leaving the bumps just as before. You'll be better off sanding down the high spots.

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i use those fake plastic credit cards they send you to make spatulas. after applying too much epoxy i remove the excess with a strip of this plastic the width of the wrap. i take the excess off the bottom while hand turning the rod. this distributes the epoxy in an even coat and i don't have problems with lumps on long wraps.