G'day mate, great way to spend a Saturday night sanding a
kit guitar. I should be tinkering on some of mine too but shall get around to that tomorrow.
Not sure if you have experienced this yet but sandpaper loses it's bite after a while, and that is without becoming clogged with shiny hard bits, as this is a signal for when you have to grab another piece of the same grit and keep going. In the middle of a post and cannot remember how far along you have got and shall break things down a bit and apologise if I dumb it down too much.
Raw, straight out of the box, run your hand across all surfaces to see how it feels and inspect closely for any glue spots or filler that will cause problems with stain coats. If you find any, time to hit them with Goof Off and it may take a few attempts to get rid of some stubborn spots. Next up is to see how bad the factory machine marks are, particularly on the edges that are 90 degrees to the front & back as these will also have end grain probably heading in a direction different to the machine cuts marks. Cutaways are notorious for this. Time to do a light sand with 80 grit as it knocks things down quite fast, and remember to do it light as too heavy handed will introduce deep scratches right up to 180 grit. Extremely important to sand with the grain, particularly on that end grain with machine marks going across the grain, as this will help to take off some of that cross grain saw cuts.
Once things feel pretty smooth with 80 time to move up to 120 and repeat. At some stage a light and slightly damp wipe over will show up any sneaky glue spots or filler that need a bit more Goof Off encouragement. Don't forget to use an old paint brush to dust off the sawdust building up as you go to help stop clogging the paper and also periodically rotate the grit paper around the sanding block too.
Again once it feels about as good as it will get, time to move up to 180 and repeat. Towards the end of 180 session you should start to notice that the machine marks are disappearing or now completely gone. Fantastic as that is when you can sand in the direction of those edges that are 90 degrees to the front and back.
240 is a level where I have used the most paper and put in the biggest effort. Also need to bear in mind that if going too hard there won't be much timber left to work on as most of it will be in a pile of saw dust. For curved tops as commonly found on LP's and many F styles best results will require you to fold the grit paper into a manageable size and sand freehand without a block. This the level where you swear your arms will drop off.
320 for me is just a very light brushing over all the surfaces. In fact as 3 out of 4 necks were coloured I actually stopped at 240 on the ones about to receive some colour.
Having used DT on builds 1 & 2 and inks on 3 & 4 the staining process was similar where the body is very thirsty soaking up the 1st coat and 2nd one doesn't take as much liquid to cover the job. At this point if using DT is to figure out whether colour is where you want to be or if it needs further stain coats to give a bit more depth of colour. Don't forget that the DT Intensifier coats bring lots of depth and vibrance. Depending on where you live local weather conditions can impact how long things take when using DT and you need to be extremely patient or risk experiencing dramas. From my experience would not recommend 0000 steel wool between coats as that stuff breaks down into very fine particles only to return somewhere later unexpectedly. If you feel you must use steel wool better buy a strong magnet to pass over the job afterwards to catch all the small fibres that could end up in the finish. My recommendation would be to do light 1200 wet sand every 2 -3 coats instead unless of course you end up with some of the dreaded patchy DT finish after last coat applied has dried which usually can only be fixed by wet sanding .
When you get to top coats, whether using DT or other products, the process is similar in that you apply thin coats without going back over yourself (overworking) as sometimes you will actually see it start to dry before you get from one side of that face to the other and going back over it will make it look like crap. You only have to do it once to know what I mean.
Again, several top coats then start wet sanding with probably 800 then 1200. Be careful with 800 as it has lots of bite and can strips things without realising before it is too late. As you apply more coats and a few more wet sandings you will start to feel the shiny smooth surface coming home and if you have enough base coats you an then progress on to the finer grits to finish it off.
Bit long winded but hopefully you can see that as there is a lot of fine grade sanding required after all coats have been done that you don't need to worry as much whilst timber is raw. In fact if using timber mate I reckon it should go on after initial 80 grit session so there is still some open grain to accept the filler.
Finally, wherever there is flame, quilt or spalted tops not a good idea to do much sanding at all. Just get it smooth and worry about getting the glassy finish much later.
Cheers, Waz
Originally Posted by wazkelly
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