As you know I have the painter here and he's been showing me some things and answering some questions I had so I thought I would pass some of it along for those who are interested.
Now the last person (not me) who did some of the painting around here didn't do a very good job so there are brush marks, orange peel texture etc. He looked at the paint in my office which is orange peel texture and told me they just 'laid it on'. Apparently that is when you just fill the roller and put it on the wall until it's covered. As I understand him, that would be something like starting at the left and working to the right and saying 'done'. This is 'laid on' and not the right way to paint.
As it is, that is merely step 1. To 'work' the paint and avoid the texture (considering you are using good paint and the right roller) you need to go over the paint one more time with the roller basically empty. He said if you imagine the paint as full of fibers you need to go over it again to make them knit together and that will help them level properly. The trick is timing as the paint needs a bit of time with the air but can't be too dry (or you will pull it off with the roller and that will cause 'flashing' which is when you see roller marks or a slightly different finish when it's dry). So he said when he's doing a wall with latex he may paint 5 - 6' of wall and then take the roller and go over it again. With oil it takes a longer time as it's slower to dry so I guess experience helps there to know when the right time to 'work it' is.
A few minutes ago I was watching This Old House and noticed the painter doing exactly this painting a wall. He did about 6' and then went back over what he just did without dipping back into the paint at all.
As for the roller, he said picking the thickness is sometimes a matter of taste but with the shiny oil in my kitchen he's using a 5 mm which is a bit thinner than he'd use with other finishes. He also showed me how to find the nap of the roller (I had no idea it had a nap like fabric has a nap) by taking a new roller and rubbing you hand from one end to the other and then turning it and doing it again (so you get the nap standing up a bit). If you look at it closely you can see that one direction makes it stand a bit straighter than the other so you now know the direction of the nap of the roller. You want to know that because if you know your preference/strength you know you press a little harder on one side than the other when using a roller and you want the nap running so it runs away from your strong side.
It's hard to describe, but let's say you like to use your roller with the handle side to the left usually (that is normally the stronger side of the roller and so more paint will be left behind on that side). If you are working from the right side of the wall to the left, that means that weaker side will be where the lap marks might be and should blend better so less chance of the lap marks and if the nap is facing towards the right, the finish will be a bit flatter. I had no idea and flip my roller around never thinking much about it until I hit near the corners. I'm going to have to try this when I do the bedroom and see if it makes any difference. he said the old time painters are really into that nap thing.
When it comes to edges, there are places in this house where last person made a real mess and you can see where the paint seeped with the tape. He told me that often happens when the edges themselves aren't nice and sharp (old house). he told me he only tapes when there is a nice sharp edge to follow as even if you tape really well, those lumps and bumps are going to make the edge looked crooked anyway. So better to do those edges by hand with a good brush and end up with what is visually a straight line. it doesn't matter if it's actually straight, it's aiming for visually straight.
If you have to paint part of a wall to touch it up or whatever, don't paint in straight lines. For instance he has basically finished my basement walls but there are a couple of spots he wants to add a bit more. He told me you turn on all the lights and look for natural shadows that may exist and use those as the edge. So where I have a shadow from a pipe, that is where he will start the touch up. He said most people won't notice thinking it's just the shadow if they see a difference in finish or whatever. where there is no such shadow he doesn't go up and down on the edge but rolls out more like hands of a clock or feathering so there is no specific line an eye might catch.
Meanwhile I can tell you this house has been full of fumes for 4 going on 5 days now. The whole basement (floor started today) and my kitchen are being done in oil/alkyd and it's killer. he was the one who recommended it but even he admits he's not having a good time with the fumes. I've used oil before but I guess when it's been a while it's more noticable and I can notice the physical effects.
One trick he's using (and I am following) is he said to drink a lot of water as the body will try and rid itself of the toxic fumes through the kidneys so having to empty your bladder a lot helps getting rid of the toxins. Haven't heard of that one before either but if it works, I'm up for it.
I find it's taking forever to dry compared to latex. I mean he started with the kitchen yesterday waiting for the paint on the walls downstairs to fully dry a whole day before doing the floors. Now as the kitchen's first coat fully dries he is doing phase one of the basement floor (we have to do phases because there are boxes and such down there). When that is done the kitchen should be ready for coat 2. Tomorrow that means he may start on the LR (with latex thank heavens) and do the ceilings after which we may be able to go move the boxes on to the phase 1 part of the floor so he can do phase 2 etc. and so on. Just that extra drying time is a pain considering I was going for some speed here and having my kitchen papered etc. for what will be 3 or 4 days means it slows me down in the painting I wanted to be doing since I can't get to the sink easily for those days (which is where I wash my brushes out and no way I'm doing that in the new bathroom sink now). Meanwhile having every window and door open and the fans going doesn't get those fumes fully out. I can't imagine how anyone would paint with that stuff in the winter and live to tell the tale.
BTW he tells me he doesn't like BM paint (not great for the price) and prefers ICI brands but his last job someone had him use the Aura paint and he was very impressed with it especially because he painted a dark chocolate brown. He said he'd happily use that again as it goes on well and has great coverage.