Hi guys, I need advices please.
so I decided to do the old hardwood floor myself. probably would save only half money than I were to hire professionals. I wasted some money renting square screen machine and realized that was not aggressive enough to sand off scratches and discoloration of the old floor. that's 100 bucks Belt sander is the way to go! so I did it with 36, 60, 100.

the important thing is I skipped buffing the floor as I saw some youtube videos skipping that step also. the second thing I skipped which I now regret is the sanding sealer(I went for natural color without stain).

here is my question or problem: after first coat of oil-based polyurethane, it's really rough and I sanded lightly with 220. they are not smooth at all as of now. Should I continue to the 2nd coat or there's remedy for the steps that I skipped. Do I need 3rd coat to make it eventually smooth enough?
I really thought I could save some time by skipping those 2 things(buffing & sanding sealer) since I was doing it all by myself and it's an old floor. thanks in advance.

It always costs double if you skip steps.

First coat soaks in and doesn't do much. If you keep adding coats you'll eventually get a good build and a smooth finish. Are you using a good flooring poly?

The first coat will raise the grain, fuzz left from the final sanding process. It always will have grain raise. The second coat will be a lot smoother,because the surface is sealed. I think that poly seals the surface well and don't use a sanding sealer. The second coat, when applied with the recommended coverage per quart should make a smooth floor. If you do apply a third coat, I think that you should wait a few days to a week before coating so the previous coats can cure a little. The floor will be ready for furniture and traffic and smell less in a few days.

I am using Minwax, dun know if it's good or not but it's most popular from the store. clear gloss. fast drying.

Are you aware of the look that a gloss finish will give you? Most floors are a semi gloss. If you want a really high end product check out Last N Last polyurethane......it'll be more expensive than Min Wax. If it's labor intensive usually a good idea to use the best materials.

I dun know how looks yet coz I just applied the 2nd last night, I will check today and if I dun like it, for the final coat can I still use semi-gloss last N last?

Yes.