TL-1HA first build

[McCreed]

One thing worth noting regarding sandpaper and grades/grit, is there is a difference between what we call 240 and what is called 240 elsewhere (mostly US). A lot woodworking & guitar building info is taken and relayed from US based sites so it can be a bit misleading FLOABW.

The differences are small but, again worth taking note of IMO. The different measurement standards are commonly ANSI in the US, and FEPA in AUS/EUR. The aggregate grade is more accurately measured in "microns" which seems to be more universal term. If you look at the attached link below, it breaks it all down.

I mention all this because when I have previously said I have gone to P320 or P400 before staining, I received finger wags of disapproval.

P400 here, is the equivalent of 320 in the US, and P320 here is slightly coarser than 240 in the US.
I think the numbers get bandied about easily without knowledge that one is not necessarily the same as the other.

I've probably explained this in a very convoluted way, but it will make sense when you see the comparison chart.
Again, probably very minor differences in the big picture, but knowledge is power!

sandpaper conversion chart

[fender3x]

One thing worth noting regarding sandpaper and grades/grit, is there is a difference between what we call 240 and what is called 240 elsewhere (mostly US). A lot woodworking & guitar building info is taken and relayed from US based sites so it can be a bit misleading FLOABW.

Wow! I was blissfully unaware of the differences. I generally go with the product mfg's recommendation on grades of sandpaper to use... but just now realized that on my last couple of projects the paint was EU while the top-coat was US.

...and speaking of the mfg's recommendations. The stain I am using has different mfg recommendations for sanding depending on a number of things. All grades given here are ANSI...

They say down to 220 with open grain, 180 with closed grain woods. You may want to use 320 with endgrain. I used 400 with paulownia which is super open grain, pine or "swamp ash" may be similar.

It get's weirder if you are using all water based products... My mfg recomended to stain first, then NO sanding until the sealcoat was down. Then 320 or 400 for scuffing between coats.

[Groovyman32]

Wow! I was blissfully unaware of the differences. I generally go with the product mfg's recommendation on grades of sandpaper to use... but just now realized that on my last couple of projects the paint was EU while the top-coat was US.

...and speaking of the mfg's recommendations. The stain I am using has different mfg recommendations for sanding depending on a number of things. All grades given here are ANSI...

They say down to 220 with open grain, 180 with closed grain woods. You may want to use 320 with endgrain. I used 400 with paulownia which is super open grain, pine or "swamp ash" may be similar.

It get's weirder if you are using all water based products... My mfg recomended to stain first, then NO sanding until the sealcoat was down. Then 320 or 400 for scuffing between coats.

Yeah - it's all so complicated! I've decided to start experimenting on scrap to see what happens - I dont have any ash so I'm just using a piece of ply that has some interesting grain to work with. I know that different wood species will have different results - but as I've not done any finishing before I just wanted to try something.

But yesterday was all about sanding. I used a rand-o sander on the top and back, started with P180 and went to P240. That took all of about 20mins (should it have taken longer?). I then spent the best part of day working the sides by hand. Either I had crappy sandpaper or my technique is rubbish - but I just seemed to go in circles, from something approaching clean looking to a bit of a scratchy mess. But I think I eventually learned to generally move in the direction of the grain, and that end grain is a pain in the arse. But I think I have it something approaching P240 all over and I'm okay with it. It feels smooth "enough" (is it?) so I'm going to use this as a starting point for finish.

Today I sanded up my ply scrap to 240 and messed about with some grain filler - just to get some experiance mixing and filling. Tomorrow I'll sanding it back and see how what happens. My idea was to see what would happen with neat grain filler (bottom right), a mix of filler and stain (top right) and neat stain (top left) which I could then fill... let's see what happens....