Can watco wipe on poly be applied to screened porch ceiling?

This could be difficult depending on how far in the stain oil penetrated the wood. Sanding removes the top stain. You may want to watch this video and see if it's something you want to try.

it has to be outside the screen to work

Are the ceiling fans on the same wall switch? And is the wall switch a 3-way switch?

Give them a light sanding with 280 grit sand paper. Clean well with mineral spirits (anything with water will raise grain and not take stain evenly) Stain cabinets with a gel stain, brush on and wipe off with a rag (check product instructions for how long to leave on before wiping off) If a darker finish is desired apply another coat after first coat is completely dry. Once stain is dry and you have the color you want then you will clear coat with a poly. First coat of poly will need to be a light "tack coat". before it is completely dry apply another coat aprox 30 mins. Let second coat dry completely prob 24-48 hrs. then sand with a 400grit sandpaper. and continue process for at least 4 coats. Dont forget to get desired sheen of poly when you purchase. If brushing on you will prob not want to use a really high gloss (may show brush strokes). Good Luck

Humidity, humidity, humidity......
and yes it will dry
good luck\
Neil

If this is on top or below (soffitt) If the cracks are movement or shrinkage when poured you can cut with Diamond grinder in a V type and then patch with a epoxy and sand fillers.If they are bigger you can use a repair motar .Your local hardware should have these in basic form.

mcdevito75 here, You say the fans are recessed into the ceiling are the fan blades blowing the air into this recess instead of outward. Also if your porch is an open porch the fans are competeing with the outside air and temerature. The only other thig to try is to lower thefans another foot.

Think we've figured out that a neighbor has the same remote code as we do and we will have to change our code. (This fan is out on our screened porch and the homes are close together here.)