Finally I manage to update this thread. Albeit I'm going to cut it into a few different posts. I'll cover the body first, then the neck in another post.
I took the guitar home and took a couple of photos in natural light coming in through the window. By some bizarre, never-to-be-repeated, quirk of fate, Nottingham wasn't grey and overcast. This is what the Tru Oil finish looks like in natural light, really nice colour and chatoyance:
I would describe the finish as being a high satin, or very low gloss. I'm sure it could be polished to a much higher gloss, but it's not the look I was after. It's 90% grain filled, meaning it feels incredibly smooth and shiny, but has a tiny bit of texture to it. It's lush! I could have gone for a complete grain fill...but again, not the look I was after. There's definitely a time and a place for a dipped-in-glass type high-gloss finish (Mmmm....sadowsky), but not when I was asked to create a Bruce Springsteen inspired guitar. Anyway, here's the lustre:
Here's my finishing schedule.
1. Sand to 400, 600 on the end grain. Obviously, sanding is critical. All scratches have to be gone otherwise they get amplified by the oil. The end grain is always difficult, especially on baseball-bat ash (which this was). Wetting the body with a sponge helps identify scratches (and raises the grain prior to finishing) as does going outside into natural light where the scratches are easier to see.
2. Seal the wood. I applied two coats of Tru Oil using a cotton rag. There's no science to this bit. Squirt some oil on the rag or the guitar then rub it in. I wiped off any excess after 5 minutes. I did this twice, 24 hours apart.
3. Grain fill using the slurry method. Using wet/dry paper on the back of a sanding block (a bit of scrap MDF) I sanded with the grain using Tru Oil as the lubricant. I know other people sand in circles (including the chap who made the video above, and his results look great) but that just makes me nervous - I don't ever like sanding other than with the grain. The idea is that the sanding dust/slurry gets trapped in the grain. I found that sanding with the grain, then using my finger to 'swirl' the slurry around worked well, and there was no danger of visible sanding scratches (which is the danger when using a circular motion). I found the best way was to divide the body up into sections and move from one section to the next (the top for example I would divide into 4), rather than trying to do the whole thing in one go. You then want to wipe across the grain to get rid of the excess. You do want to make sure you wipe off all the excess, otherwise you find that you end up with ridges or streaks, which can then be hard to sand away when you move up to the finer grits. If you are anythnig like me you'll find it a pretty messy business - always dripping down the sides, or onto the top you've just wiped, and onto your work surface which then get's smudged onto you newly wiped guitar top etc etc. None of which is a problem, just wipe. I wiped off with standard kitchen paper. Keep lots and lots to hand. I repeated this process twice, both times using 400 wet/dry and seperated by 24 hrs. I found that his filled the grain to a bout 90%, which was the look I was after. A third time would probably have been enough to get the grain completely filled, if you were wanting a completely smooth surface on which to build a high gloss finish. I found the slurry was very happy to stay in the grain, wiping with the kitchen paper took the oil off the surface but leaving the grain nicely filled.
3. Smoothing. I find it usefull to seperate in my head the process of grain fill, and sanding smooth. The process is much the same as above - using wet/dry paper on a sanding block, sanding with the grain then throroughly wiping off the excess. I did the following grits:
600, 800, 1000, 1200, 1500, 2000.
It was really at 1500 where there was a sudden change in lustre, from what I would call satin to a low gloss. The great thing about tru oil is that you really just keep going until either your arms fall off, or you've got the appearance you want. It is quite a physical process - from 800 and above I would vigorously rub off the excess oil (again, in the direction of the grain), pressing hard to generate a tiny bit of heat. I did only one grit per day, but I'm told doing 2 per day is no problem.
Another thing I tried was using Mirka Abralon sanding pads rather than wet/dry paper. It worked really well, and was definitely less messy as the oil gets absorved into the foam of the pad. It did, though, use a lot more oil. I'm not sure the effect was any different though, both worked just as well.
I left it at that, ie my last coast was sanded with 2000 grit. For a higher gloss (without buffing) I understand you can just apply a very thin coat with a cotton rag as your final coat. I didin't as I liked the finish as it was.
4. Waiting.......I wait at least a week before putting the guitar together. I think Tru Oil takes that long to harden sufficiently.
Overall, I'm very happy with how it turned out. Using Tru Oil on ash is not an easy option. Then again, ash is never an easy option whatever the finish you're using, the grain is just so open. But if you don't want to spray then it's a finish you can apply on the kitchen table. Just make sure that you have wiped away every trace of oil at the end of each session or you'll have to go back down the grits to get out the ridges.
I'll go through the process for the neck tomorrow.
Cheers all.
And thanks very much to @Andyjr1515 for his help and advice re Tru Oil (amongst many other things!)
Hi. This is a great breakdown. Thankyou. Can I just ask, when you're smoothing, going through the grits, is that done with Tru oil as the lube or are you sanding to that grit, then applying the Tru oil?
95% Tru oil finished guitar - A How to Guide
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Hi. This is a great breakdown. Thankyou. Can I just ask, when you're smoothing, going through the grits, is that done with Tru oil as the lube or are you sanding to that grit, then applying the Tru oil?
Thanks!