Baseboards over carpet

I'm finishing a guest room with new baseboards and doors. This room will have carpet installed so I'm installing the baseboards off the floor to allow clearance for the carpet to be tucked under. This provides a much nicer aesthetic, allowing the carpet to flow under the base.

To do this I've cut scrap trim at 7/16" on a table saw (exactly 7/16"!), then chop into 3 or so inch segments to use as spacers. I've read 3/8" seems to be the standard but no one says anything about the carpet thickness, so how can 3/8" work for all carpet? I opted for 7/16" since I will have a 1/2" pad and moderately thick carpet. You have to be careful that if your floor isn't even that you don't end up with 1/2" or higher gaps in areas or you would see gaps between the base and carpet. The base I'm using is 4.5" and doesn't like to bend much, although it will some, but my floors were mostly level so wasn't much on an issue.

I paint the base before installing so I don't have to cut in the paint along the wall. On sawhorses I sand and prime (oil base) the base. Then I paint one coat on the entire base and  second coat on just the top, where it meets the wall. After installing the base I just need to fill the nail holes, sand and spot paint. Then I paint one final coat on the entire base, except of course where it meets the wall. I really like this approach, with the only downside being that the base can have some slight gaps between the wall in places, but mostly it's tight and the perfect line (no paint spilling onto wall) makes it worth it, along with time savings in not having to cut in. For the next paint job it will get caulked to fill in any gaps and painted as typical. Also, for the corners and where it meets door trim, I can caulk to the wall but it's very subtle and again I think worth it

Oil first, then Latex

I've read varying accounts about whether oil can go over latex or latex over oil. The consensus is yes on latex over oil but maybe not oil over latex. Anyway, the point about this post is to never, ever, ever use a latex primer on bare wood since it has the tendency to raise the grain in the wood. Here's what you might get

Notice the diagonal ribbons on the door jamb. That area was completely smooth before painting but the water from the paint raised the grain. When this happens you kind of have a mess. You can sand it down but latex doesn't sand so great, especially before it cures. Then you'd have to use an oil primer and then it's safe to apply latex. This is pine and I'm sure some wood varieties don't have this issue as much. I've noticed alder to be fairly stable with latex. Cedar doesn't have a raised grain but does leak tannins through latex, so oil base is essential. Also, I've noticed not all pine has this issue and it depends on the cut of the wood, with the quartersawn/end grain being mostly resistant to swelling and lesser cuts (most of what you encounter in paint grade/finger joint) being problematic.

So, for me, always oil primer on bare woods, then latex. The oil effectively seals the wood so the water can't mess with the grain

Replace Your Brush

I wasn't paying much attention to my brush (purdy nylox soft sash 2 1/2") Here's the old and new side by side. Not surprisingly the new brush results in a much smoother finish. The brushes are also not expensive when taking into account the cost of a good quality paint $50/gal and your labor, so makes sense to replace before they get too worn. Same brush but they changed the design.

How Not to Get Rust Flakes in Your Paint

tldr; Use a rubber mallet, not a hammer, to close your paint cans. Don't allow paint to collect in the rim or it will rust and ruin your paint. Also its best to use a paint tool instead of screw driver to remove the lid so it does not deform. If this does happen then read on.

I started some trim paint work a few months back and recently when I opened the can I noticed rust all over the lid. I painted with it and sure enough there were rust flakes here and there on my trim. This sucks! I went to the local paint store and the salesguy looked at me like I'm just a biggest moron he's ever encountered. He wasn't able to articulate the why it happened but I figured it out. I was closing the paint lid with a hammer. This deforms the lid and when that happens you get air pockets where the lid meets the can. The ingredients for rust are #1 Steel, #2 water #3 air. Second mistake was to allow paint to collect in the top of the can where the lid goes.

So, to resolve this issues, with Ben. Moore paint at $50 a gallon I'm not interested in tossing it. I bought an empty can for $3, a mesh filter, and poured the paint from the rust can to the new can, through the filter. I'm not certain the mesh was fine enough to filter out the rust but we'll see. I'm only using this paint for the first coat so if it does still have rust then I can sand and remove before the final coat. The guy at the paint store mentioned that panty hose can also be used to do the same thing.