Infinitum

[Bizman62]

2 hours ago, Akula said:

f-holes, nuts, and horns all around! What a provocative business this is!

[Akula]

I'll start this with the standard every-clamp-in-the-shop photo.

 

The method of radiusing the body wings with a router sled then cleaning up with planes and scrapers yielded fairly good results, but at the end of the day the human touch means it would never be 100% accurate, and anything less than perfection could create glue lines between the top and the wings. I had a backup plan for this - if the glue up revealed glue lines, I was going to add abalone binding. Luckily, and I mean by pure luck, the join was great! No binding is required, although the idea is still tempting me.

Here's the instrument united. The control potentiometer recess dishes were a last-minute idea, but I really liked the way they looked on my double-cut build a few years ago, so I did them again.

 

Routing the body shape was a touch more complex than on a normal slab-sided electric solid body instrument. Being that the top and back have a radius, the sides are not perpendicular. And, as the x axis changes, so does the angle. I considered using my radius jig and sled, but after a quick freehand pass I was quite confident with my ability to follow the lean with the router, so I did it all without the jig. 

Foolishly, I managed to tear-out a bit of walnut on the treble side bout. That's twice on the same build! Ah well, the best thing about tear-out is that you now have a perfectly jointed piece to glue back on, as long as you can find the bit that flew off. I carried on with the day, and just put some blue tape around the parts which are not shaped yet, and I'll finish that part tomorrow after the chip's been glued back on.

 

Roundovers. I'm using an R19mm roundover bit, which is absolutely fucking terrifying to spin at high rotations. It's half a pound of metal with carbide blades attached to it, and I'm going to fly it at thousands of rpm and slam it into some timber? Sounds great.

To take some of the pressure off the gigantic death-bit, I used a 12mm roundover first. I got a lot of burning on the blackwood top, and I mean heaps. This is why we test and take small passes, to figure this stuff out.

 

I figured my rpm was too high, and the feed rate too slow. The feed rate was slow because of my need to control the router around the horns, and keep my balance on the radiused top, so I slowed the rpm and went for the big-boy router bit.

 

Some amount of grain fuzzies and burning will have to be accepted, due to the blackwood's long interlocking grain and high tendency to scorch, but I think this will do just fine. The roundover cut was stopped way short of centre across the thickness of the instrument - trust me, a perfect semicircle profile both looks and feels very strange. The hard line between curve and straight will be smoothed out right before the finishing phase, probably using scrapers due to my new found affinity for that particular tool.

 

Glued the blow-out back on so I can shape the lower bout of the body tomorrow, and left it for the night. Glued the headstock backstrap while I was at it.

 

 - Jam

[Bizman62]

That's starting to look like something I'd like to copy build an "inspired by" version!

[Asdrael]

Looking great, and nice write up!

 

The scrapper is tempting to use for smoothing out transitions but I have found that it has a tendency to grab a bit easily when the grain changes directions (aka a body contour). I did mine with some p180 at the last sanding stages (after staining actually) wrapped around my finger tip being careful not to scrap the top itself and it was both more easy to control and gave a more natural transition I find.

[Akula]

On 7/6/2024 at 4:16 AM, Asdrael said:

The scrapper is tempting to use for smoothing out transitions but I have found that it has a tendency to grab a bit easily when the grain changes directions (aka a body contour). I did mine with some p180 at the last sanding stages (after staining actually) wrapped around my finger tip being careful not to scrap the top itself and it was both more easy to control and gave a more natural transition I find.

Good point, this is true. Especially with the blackwood top and it's interlocked grain! Sharp tools help a lot, but sometimes sanding is just the way forward.

 

Roundovers all done, plus a little carve on the tail. 

 

Next item to tackle was cutting fret slots. It's a multiscale, and a wenge fretboard, so I slotted it while it was square so that any chip out from the saw would be removed after I cut it to taper. Of course I couldn't use my mitre box setup, so I clamped an offcut of acrylic to act as a saw guide. Being multiscale, I marked out the outermost string paths and marked the fret positions of each, then drew a line between the two points, checked the angle of the line against my CAD drawings, then scored the line deep into the wenge with a scalpel. I tried to simply print out the fretboard plan, tape the pieces of paper together, and cut through that - but my printer is consumer grade, and has a measurable inaccuracy across the page. Better to measure it with steel rulers and callipers, the old fashioned way.

 

And here we are, all glued up and tapered. The truss rod and carbon fibre rods went in at this point - I used 6x6mm CF instead of the normal 6x4. I'm hoping the extra stiffness makes a difference on this thin neck against the pull of five thick bass strings.

 

While the fretboard was gluing up, I shone a bit of attention to the smaller jobs which usually get left to the very end - cavity covers. 

 

My usual process of laminating timber and steel to form a cavity cover, held into the instrument by magnets, works quite well. However, I've discovered with a few of my own guitars that I can actually lose the cover while playing a particularly violent punk rock show. Stacking magnets will help, but a mechanical solution would be better - and something more eloquent than going back to simple wood screws.

 

Thumb wheels. I recessed them into a dish using the same process as my potentiometer dishes. The bolt screws into an M4 brass insert, and the wheel stands proud of the body by no more than surface mount string-through ferrules on a normal guitar. The magnets are still doing the vast majority of the holding power, lest the cover flap around: the bolt just holds the cover close enough that the magnets never lose their attraction due to a small separation and the inverse square law. All up, I think it looks rather sharp.

 

The truss rod cover just got the magnet treatment, but with three magnets stacked, and the cover itself inlaid into a recess tight enough to grab the steel. Headstock got shaped, and the tuners also recessed with a 20mm forstner bit. I didn't have to recess the tuners, but it fits with the style of the instrument, and it's the small details which matter.

 

At the last minute before radiusing the fretboard, I decided to inlay an infinity sign into the 12th fret area. I am a fake luthier, and completely terrified of inlays, and so I have always chosen to do round-shaped things which can be accomplished with a drill (except for a rather disastrous attempt at block inlays last year), and I figured an infinity sign is basically two circles very close together with the middle bit chiselled out. Easy life. The inlay material is aluminium tube, and I'll put some abalone in the middle when it arrives in the post, then sand the lot flush with the radius and polish to all hell before whacking some frets in.

 

One last image before I sign off for the night - that headstock turned out alright with the face veneer and the backstrap. Looks almost like an ice-cream sandwich.

 

 - Jam

[Asdrael]

Hey don't go too fast I want a shot at GOTM

 

Looking great! Thumb wheels are a good idea for your problem, although I have to admit that I basically never look inside the cavity once the soldering is done. So I am generally happy with old school screws.

 

I like the recessed tuner washer stuff though, will steal that for the next one. Although that means you need 1mm extra thickness to accommodate I suppose?

[Akula]

35 minutes ago, Asdrael said:

Hey don't go too fast I want a shot at GOTM

 

Looking great! Thumb wheels are a good idea for your problem, although I have to admit that I basically never look inside the cavity once the soldering is done. So I am generally happy with old school screws.

 

I like the recessed tuner washer stuff though, will steal that for the next one. Although that means you need 1mm extra thickness to accommodate I suppose?

Haha! I've never entered a GOTM before, but your current build is already into the finishing phase while mine doesn't even have frets yet. You'll get this one for sure mate 

 

The extra thickness was a consideration, definitely. I'm not in the workshop at the moment and thus can't provide measurements, but I think my covers are about 3mm thick, 2mm of timber and a mil of steel sheet. The body is 39.5mm with a 5.5mm top, with I think a 26mm cavity, leaving an 8mm back, into which I routed the 3mm "shelf". That leaves 5mm for the magnets on the shelf, and the brass insert. The thumbwheel, as mentioned, stands proud of the back by about a mil, which is little enough to not be a huge protrusion but big enough to get your fingers around to unscrew. 

I must agree, for most guitars in the world the simple wood screw will suffice. Honestly, I started using magnets because I saw all the high-end luthiers doing it, and it's a nice touch. A few months ago after a show I was amazed when somebody from the audience handed me my own magnet-held cavity cover back to me and said it had flown across the stage during what I thought was a fairly docile performance. Either my magnets aren't strong enough, my cavity routing technique sucks, or I'm a nutcase on stage.

 

I've got all of the fretwork and neck carving to accomplish yet, but I'm already thinking ordering a tin of Osmo instead of my usual Danish Oil. @Asdrael and @Bizman62 recommended a few products already - I'm thinking about 3011 gloss? Unsure of whether an oil product can create much of a gloss patina, but it's all about the wood preparation, right?

 

 - Jam

[LFlab]

Looks fantastic, good to see that you managed that compound scarf joint. Really like the profile and carving on the body end, definitely Alembic vibes.

This months GOTM will be extra exciting! 

[Asdrael]

34 minutes ago, Akula said:

Ha I'm already thinking ordering a tin of Osmo instead of my usual Danish Oil. @Asdrael and @Bizman62 recommended a few products already - I'm thinking about 3011 gloss? Unsure of whether an oil product can create much of a gloss patina, but it's all about the wood preparation, right?

 

Keep in mind my Osmo is still curing but already 1 week in (out of 2) so I have a good idea how it's going to end up being.

Anyhow, I ran quite a few tests on scrap wood using their free sample bags (get in touch with them they'll send you up to 5x5mL for free). I ended up with this:

- Rosewood (neck): Prepared with up to P400 and used Osmo extra thin 1011. Three thin-ish coats with 24h between each, wipe-on vigorously / 5 min / wipe-off vigorously. Ending up with a waxy wood feel, non sticky and can still feel the texture. Satin look. Less plastic feel than 5-10 coats of Tru-oil and I hope better protection.

- Swamp ash: Prepared with up to P400 and used gloss Polyx 3011. Same process as the rosewood (3 coat wipe on/off), but one pass with 0000 steel wool before the last coat. Ended up a bit too glossy for my taste but not that glossy. Can still feel the wood texture pretty well.

- (figured) Maple: This one was more interesting. They recommend using 1011 but I didn't really like how it turned out on the scraps. After a few tried, I prepared with P400 and did 1 coat of 1011, followed by 3 coats of 3011. The 1011 is supposed to penetrate better (strong suspicion it's actually 3032 diluted 50/50 with terpentine). All of those with the wipe on / 5 min / wipe off, one pass with 0000 steel wool before the last coat. Ended up on point: glossy but not mirror like, can still somewhat feel the maple. If the protection is as good as they claim, it's a winner for a maple top. I am fairly sure I could buff it or wet sand it and apply a coat or two more this way for a very high gloss but I am not aiming for that.

Hope that helps. Feel free to ask more if anything is unclear. I can take pictures for you once it's fully cured (I don't suspect anything will change tho).

[Akula]

23 hours ago, LFlab said:

Looks fantastic, good to see that you managed that compound scarf joint. Really like the profile and carving on the body end, definitely Alembic vibes.

Thanks! The compound scarf was much more straightforward than I thought it would be, thanks to a lot of the legwork being done by this dude. Definitely helps to have a basic understanding of the mathematics involved, but if not then the cheat sheet provided works just fine. As with all scarf joints, it all comes down to how well you clean it up after sawing, in my case done with a Stanley No. 4 which is probably older than I am.

 

@Asdrael thanks for the info! The timbers I'm using are mostly open-pored, walnut on the wings and blackwood on the top. The maple is dense enough I can almost wet-sand it to a shine anyways, but for the other timbers I'll be doing a slurry coat, wet sanding the oil into the wood to use the sawdust and oil as a grain filler. Is this something you've done with Osmo? I'm sure it'll work exactly the same was as other oil products. Blackwood is a funny Australian timber, I've found it to be quite oily in itself - last time I did a Danish Oil job on blackwood, I had to constantly wipe off the oil as it would come flowing out of the open pores for hours after application! 

 

Managed to fit all of my fretwork into one day today. I do love the winter months for this - we get weeks with no work at all, then sporadic gigs, then busy weeks, then nothing - so it's quite easy for me to spend a whole day in the workshop if I plan my life properly.

I cut my frets to size, then shape the semi-hemi fret ends on the bench grinder, nip tangs, then file and sand to p1000 the ends before installing. It's time consuming to a point, but within three hours I've got all the frets dressed and ready to go. I prefer this way as opposed to installing oversized frets and bevelling flush, especially on neck-through guitars where the body can get in the way of tools for end dressing. I'm afraid this is a rather bad photo - modern smartphone cameras have come a long way, but have yet to compete with a proper macro lens.

 

That inlay turned out.... okay. I think the abalone dots made the difference, but unfortunately what I thought was a perfect join between the two aluminium parts was not in fact perfect after sanding down to flush. Damn! At this point I had the options of accepting it, or attempting to drill it out and re-doing it with the danger of tearing up all that wenge and aluminium. I went for the former. I sanded the wenge up to p1500 and drenched it in oil.

 

Frets.

 

Lovely.

 

Now I think about it, inlay doesn't look too bad to my eyes. A friend also told me: "It's a 5-string, right? Nobody's going to see the middle of the inlay." Haha! My roadie mates are quite practical.

 

Next jobs involve carving the neck, heel and volute. Then I'll need to route the bridge, tailpiece, and pickup bays. Owing to the accuracy of CAD drawings, I probably could've already routed these parts, but there's something sacrilege about setting the position of a bridge without having a fretboard in place with it's nut defining an absolute physical position of the start of the scale length. Now I've got that, I can get the last routing operations done, carve the neck, and start the endless phase of sanding and finishing.

 

 - Jam

[LFlab]

Looks great, totally dig your way of doing the fret ends, I have seen people do it this way on bound boards, but it hadn't occurred to me that you can do this on unbound fingerboards as well, and it does prevent one gouging the fingerboard, just need to be very precise with cutting to length. Do you account for the fret becoming less radiused when you hammer it in (assuming there's a slightly tighter radius on them than the fingerboard)?

[Asdrael]

Looks good! I really like how the inlay turned out. I think it would be easier with copper though, as aluminium bends so easily I would be scared to.move it with sanding.

 

For the Osmo stuff I don't slurry sand or even pore fill before application. I like a "raw" application. If I am not mistaken, @Bizman62and @Andyjr1515are the resident slurry sanding experts. What I forgot to mention is that I always wipe with naphta before applying Osmo to make sure there is as little oil on the surface as possible. Look also at their wood / Osmo product recommendations they are pretty spot on. But as usual, a trial run is worth a thousand words.

 

How do you like blackwood so gar and do you know how it sounds like? Looks attractive as a neck wood for my next build...

[Bizman62]

@Andyjr1515 is the slurry guru, I'm just trying to follow his advice.

[Akula]

On 7/15/2024 at 2:24 AM, LFlab said:

Do you account for the fret becoming less radiused when you hammer it in (assuming there's a slightly tighter radius on them than the fingerboard)?

Yes, although the difference between the two arc lengths is a lot less than you'd imagine. Here's a quick CAD drawing to illustrate my point: the top arc is the fretboard surface, a larger flatter radius, and the arc below it is the 10" radius of the pre-radius fretwire. The difference between the lengths, over a 66mm width of fretboard, is about 0.12mm. So yes, I account for the frets becoming slightly flatter and therefore "longer", but we're talking about kissing the fret end with a file and re-measuring with calipers.

 

On 7/15/2024 at 2:53 AM, Asdrael said:

I think it would be easier with copper though, as aluminium bends so easily I would be scared to.move it with sanding.

Oh definitely! I like using aluminium because it's very easy to work, but the two halfs of my inlay didn't end up meeting perfectly, which probably wouldn't have happened if I'd used copper, or probably brass. I'll be using brass later on with this build for a custom nut, keen to learn how to work with it.

 

On 7/15/2024 at 2:53 AM, Asdrael said:

How do you like blackwood so gar and do you know how it sounds like? Looks attractive as a neck wood for my next build...

I adore blackwood. It's plentiful in this country, and very easy to find lovely figured boards. It's generally quite easy to work, but it's wavy interlocked grain can be a pain to plane and route - careful sanding is a great way to take it to a finish. Speaking of finish, it takes oils very well but needs to be grain-filled for a poly clear coat. As for tone? Well, I love the sound of my blackwood-topped double cut guitar, but for a more subjective/objective opinion: https://rwguitars.com.au/blogs/news/weissenborn-tonewoods-tasmanian-blackwood

 

I routed the bridge, tailpiece, and pickup bays. I do love these neck-through builds, where routing through the top reveals this lovely layered sandwich of timbers.

 

Neck carving. Common tools here: rasps, files, scrapers, sandpaper. I went for a fairly wide and flat U-shape, modelled off my Tele build from last year - that neck is ultra thin and feels amazing to my hands, so I copied it here.

 

Volute in it's rough shaping process. 

 

And here it is, a little more ready for use. The volute had me really scratching my head for a while - it falls between the nut and first fret, on the treble side, but on the bass side it's right under the first fret, due to the multiscale. I was afraid it would feel really weird, so I left enough meat to be able to move it back if needed, but it actually came out feeling pretty natural. While doing some compulsory air-guitar dance moves with my new and unfinished bass guitar, I found my left index finger smacking down on the fretboard right behind the first fret on instinct. 

 

Here's the neck heel. Hard to tell from the light, but the line between body and heel is rather square, leading down to the flat U shape of the neck. I like it - the neck goes from about 19mm thick at the nut, to 22mm at fret 18, to full body thickness right before fret 24. Again, these neck-through instruments really allow me to get the ergonomics right.

 

Here's a full shot, right after spraying a bunch of metho. 

 

I've started the sanding process, but I still have one proper operation left before I can start finishing - headstock inlay. I've so far managed to get away with engraving my logo onto steel truss rod covers or headstock badges, working out rather well, but I figured I'd try actually cutting out and inlaying a piece of pearloid. This completely failed. I have a coping saw with adequately thin blades, but I just cannot recreate the accuracy and crisp lines of such a small piece. This is a skill I need to learn and perfect if I want to continue making musical instruments, but I doubt I can perfect it in time to complete this instrument. So, I'm going to engrave my logo onto a 25mm steel circle, and inlay that whole piece into the headstock, possibly with an abalone or pearloid ring around it to mirror the 12th fret inlay. Circles are easy, intricate letters are not. More to the point - better to do something simple and do it well, than do something complex to a bad quality. 

 

So, on the centreline, or above it, or below it? I haven't left myself much room!

 

 - Jam

 

[Bizman62]

18 minutes ago, Akula said:

So, on the centreline, or above it, or below it? I haven't left myself much room!

I would be tempted to put the logo into the place of the sixth tuner washer. Well, that would actually fall below the alignment of the second string but visually that would add symmetry and the logo would have some space around it.

[Akula]

@Bizman62, considering my only other real option is to go above the line, I think you're onto something!

 

Check out this abomination:

 

Anyways, this is something I should've been thinking about two months ago when I started drawing plans. Good lesson learned.

 

 - Jam

[Asdrael]

What about moving the circular logo to the truss rod cover and engraving the back cover plate instead?

[Bizman62]

3 hours ago, Akula said:

Check out this abomination:

That's why I didn't suggest that...

 

[FauknaciousD]

On 7/13/2024 at 8:38 AM, Akula said:

Stacking magnets will help, but a mechanical solution would be better - and something more eloquent than going back to simple wood screws.

Sick build so far! Liking the dark wood with the F holes, feel like most F hole axes are a lighter color.
 I had thought about using magnets on the backplates on my last build but opted against it for simplicity and not wanting to accidentally lose the backplate when playing. The thumbscrews look good, they aren't in a location anything would snag on em? (Don't know if your wardrobe is nothing but tassels and ripped clothing lol)
 

[Akula]

22 hours ago, Asdrael said:

What about moving the circular logo to the truss rod cover and engraving the back cover plate instead?

I actually thought the engraved cavity cover on your last build was stylish as all hell! I've been engraving the inside of my steel cavity covers for a while now, but this instrument definitely needs at least the "J" on the headstock - I'm proud of this one!

 

26 minutes ago, FauknaciousD said:

 I had thought about using magnets on the backplates on my last build but opted against it for simplicity and not wanting to accidentally lose the backplate when playing. The thumbscrews look good, they aren't in a location anything would snag on em? (Don't know if your wardrobe is nothing but tassels and ripped clothing lol)

Magnets, in my opinion, are great for battery covers or for a cavity which holds a battery - something you'd actually need to open once a month or two. If it's just a passive guitar where you might need access to the electronics only for maintenance or a pickup change, then screws are definitively the simplest solution. Magnets are pretty damn cool though. The thumbwheels I'm using are to allow for that coolness while avoiding the issue you've described - I have absolutely lost cavity covers on stage. They're recessed, so they shouldn't snag on anything while performing. My wardrobe on stage? Well, I could always just play gigs in my birthday suit....

 

Two days of shed sessions got all of my sanding work done. I went old-school and did it all by hand, without my palm sander or sanding drums. I did try using sanding drums in the tight corners where the cutaways meet the neck heel, but I found I was creating some low grit scratches which would be increasingly hard to remove later without taking away a lot of material. This phase is part of shape-sanding. Anything below P240, I deem to be noticeably changing the geometry and shape of the timber, hence shape sanding.

Next up was finish-sanding, the objective difference being to remove scratches and machining marks. There is of course some crossover, like, you'd better be sure to remove any rasp or file marks before you get higher than 240, but it's a reasonable thing to divide your attention between getting the sharp lines of the roundover dialled in with lower grits before trying to polish the end grain at the top of the headstock. 

I hardly used sanding blocks for the top and back of this guitar. I'm well aware that if you sand anything without a block it will not end up flat, but this guitar is radiused, so I was afraid of the edges sticking into the back, or creating more of a flat on sections of the top. Luckily the top and back only really needed fine grits.

If memory serves, I went to P240, raised the grain, P240 again, raised grain, P400, raised grain, P400 again. This is what I ended up with.

 

First coat of 3011 on the cavity covers:

 

Headstock too...

 

Having never done a backstrap veneer before, I really like the way this turned out.

 

I didn't get a good photo of the top, so a nice shot of the back shall have to suffice.

 

First impressions of Osmo. It's a lot thicker than I had expected! Especially for a slurry coat, I found I had to use quite a lot of product to get a thick enough coat to wet-sand the timber. I sanded with the grain and wiped off at a 45' angle. Because wet sanding takes a fair bit longer than just a wipe-on wipe-off application, I realised the oil was starting to get sticky on the surface before I'd gotten around to wiping off, so I had to really hustle to get it done and wipe off before it went tacky. I'm really interested to see how it shows up tomorrow - I'm hoping the grain is filled sufficiently and I can just get away with one or two more light coats of wipe on and wipe off, then possibly a lick of 0000 steel wool to knock down any fibres and bring a shine to it.

 

I've ordered a flat bar of brass stock, some grub screws and cap head screws, and will be crafting an adjustable multiscale nut. I've never been much of a machinist, but given the lack of a market product, I figured I'd give it a go. That's what it's all about. If I fail, I can always just make one out of bone or something.

 

 - Jam

[Asdrael]

That looks great.

 

Yeah the Osmo is pretty thick. For a slurry, maybe an initial coat of 1011 would have been easier to work with as it is much less viscous. Looks great from here though and I am sure a scrubbing with 0000 before the last thing coat will make it look and feel great!

[Bizman62]

1 hour ago, Asdrael said:

the Osmo is pretty thick. For a slurry, maybe an initial coat of 1011 would have been easier to work with as it is much less viscous.

I have a very faint memory about thinning Osmo with fir turpentine. If memory serves me right that was something I heard from the guy that sold me the very first can some three decades ago, the owner of a lumberyard/cabinetmaker. Then again the importer's agent advised against doing that. On our main page there's a quote from this https://www.popularwoodworking.com/finishing/you-can-add-all-the-thinner-you-want/ which may or may not encourage you to add anything to the product you're applying on your masterpiece.

[Akula]

It's a funny one with slurry coats - you've got to work fast to allow the oil enough time to pull the sawdust into the wood grain, and be careful not to wipe it away in the wipe-off. That's where a less viscous product would be useful. I'm really happy with the feel of the wood after the first coat, so I'll be doing a few more normal applications without wet sanding. 

@Bizman62 interesting link! I was under the impression that PolyX is sold as low-VOC, but that could be the Mandela effect. Would make sense, though, being as thick as it is. I've got a whole tin of the stuff, I'll do a few test pieces on offcuts to explore thinning the product and taking my time with wet sanding. Oil finishes are unique in the way that they don't build up, they penetrate and sink in, and there comes a point where you literally can't apply more oil because the wood won't accept any more, and therefore you need to kind of just get it right before the wood has drank all it can drink. Temperature also plays a part in that equation. If I could get three or four rounds of wet-sanding, say, P400 through to P800, I am confident I can create a flat, smooth, oil-based finished surface. On the next build, of course. 

 

Anyways, I'm really happy with the way the first coat has dried. 

 

Owing to the bleak Sydney midwinter, temperatures overnight are a far bit less than the 25'C implied by the instructions for a 12hr drying time. I checked on the instrument after ten hours, and found it still tacky - I am hoping to some form of deity that this will dry, and that it isn't due to my extended time of application when I was panicking to wet-sand and rub off. It's mostly the maple which is still a touch sticky, though, which I didn't wet-sand at all, but I did delay rubbing it off due to the overall process. 

I'm going to wait another day - a string of load ins and load outs are consuming my time this weekend - then apply coat number two. If I've ever learned a lesson as valuable as this: don't ever rush a finish job! 

 

 - Jam

[Bizman62]

15 hours ago, Akula said:

I've got a whole tin of the stuff, I'll do a few test pieces on offcuts to explore thinning the product and taking my time with wet sanding. Oil finishes are unique in the way that they don't build up, they penetrate and sink in, and there comes a point where you literally can't apply more oil because the wood won't accept any more,

As you may know from my posting history I've been toying with BLO, turps and solvent based poly, mixing my own version of TruOil or Danish. The recipe is ancient and very simple, in the oldest version they used fir pitch instead of lacquer - violin makers still may do that as is shown here: https://youtu.be/gh5JTATnl4k?feature=shared . Making that can be scary if the hot ingredients catch fire!

Another ready made similar product is the traditional French boat varnish called Le Tonkinois. It's a mix of Tung and Linseed oils with some sort of resin and solvent. As you may know, Tung oil hardens even harder than BLO. I've been planning to buy both a small can of Tonk and some Tung oil to test if I can mix a similar product from scratch. I'd also like to get some Alkyd resin (or whatever that actually is) as such instead of a ready mixed poly but I guess they don't sell it for consumers.

The reason to add lacquer/pitch is to make the stuff build up, level pores and improve shock resistance. From the recipes I've found online any solvent based poly should work as long as it says on the can that the tools can be cleaned with turpentine/mineral spirits. It's all about adding resin in some form. I've been using fir turpentine for solvent as it's a natural organic product but I guess white spirit would work as well.

After this long prologue, one idea I've been thinking of is to mix Osmo with Alkyd poly but I don't have them in the house at the moment and buying a full can of both just for testing would be wasted money. Are you interested in mixing a spoonful of Osmo and some poly and turps? That quantity should cover an area of one square foot at least once.

 

[Akula]

5 hours ago, Bizman62 said:

Are you interested in mixing a spoonful of Osmo and some poly and turps?

Yep, I can do that! What sort of metrics are you interested in studying? Are you thinking of total number of coats for a smooth surface, on open or closed grained wood, straight application or slurry method, etc. Give me a day or two to get through this K-pop gig, but I can get into testing next week mate.

 

Dropped into the shed tonight for all of half an hour. The first coat has finally dried, so I gave everything a quick rub-down to remove any dust and burnish off any furry wood fibres, and gave another coat of 3011. This time, no slurry wet sanding, just a quick and light cover using a lint free rag. It was so damn light I didn't even wipe off, because I only used enough product to slightly change the reflection of my work light. The instructions from Osmo told me: "If in doubt, use less.", so I did. 

 

 - Jam