Sanding (and finishing) A1 Cherry Plywood to match solid Cherry in same project

[smorgasbord]

I'm building a Murphy bed, which is my first big use of plywood for outside-visible surfaces. Previously, I used pre-finished maple plywood for the inside of kitchen/bathroom cabinets, but the outside surfaces were all solid wood frame and panel.

So, I found some pretty nice (better be for $180/sheet!) A1 graded Cherry plywood. It's cross-banded veneer core - MDF core was going to be too heavy for the bed mechanism and not as strong for the sides that hold up everything.

My plan is to "frame" the plywood panels with overlaid ¼" solid Cherry to make them look like Shaker style frame-and-recessed-panels, which matches the real frame-and-panel I've used elsewhere (including all the doors). My concern is sanding so that when I apply finish everything looks like it's all just solid wood - or at least looks all the same. I'm also a bit worried about sanding through the veneer.

I've started cutting the panels (first time I really needed that track saw, so the upcoming Festool tracksaw is on my purchase list) and while I haven't shown light at a low angle on them, my first take is that they appear to be sanded well. I have some scrap pieces on which I'll experiment, but I thought I'd ask for advice/tips on what to try first.

Since it probably matters, I'll be using some kind of oil finish. I want something very low-sheen. I've used pure tung oil for my interior doors, which is great but takes a long time to really dry. I've used Sutherland Welles polymerized tung oil wiping varnish on some things, and that's what I'm leaning towards here.  But, I could be convinced to try a hard oil like Odie's Oil (I bought a 3 jar set a while back that I haven't yet tried) here as well.

As for sanders, I'll be putting the solid wood through my dual-drum sander (100 & 150 grit, maybe 80/120 if the 100/150 doesn't get the planer ripples out completely), and then I intend to follow-up with my brand-new LS 130 linear sander with Cubitron/Granat grits. Previously, I've actually hand-sanded everything coming off the 150 grit drum sander, usually starting with 220 grit (but sometimes going down to 180 depending on how fresh/clean the drum sander belts were).

-> Now for the real question - what how should I sand the plywood?

I'm thinking that I could start with 220 grit on the LS 130, same as I'm doing with the solid wood. I know the LS 130 is primarily designed for profile sanding, but I'm expecting that the linear action of the sander will make it great for finish sanding of any flat board as well - and make it go faster (and cleaner with dust extraction) than hand sanding.  I'm also thinking that I should even tough my old Bosch random orbit sander, as there's no need to do any stock flattening or such, and why take the risk of introducing swirl marks on well-prepped stock that is already medium grit sanded?

Advice, tips, musings, etc. all welcome.

Heck, even advice for finishing cherry welcome. My last cherry project was a cradle for my son, which was made from one giant cherry board. That meant I didn't apply any stain or anything since I didn't have to even out the color. In the decades since the cradle has darkened nicely and I'm very proud of it (my first large-scale dovetails, too). But, for this project, with plywood and various cherry boards, should I be looking at apply some kind of light cherry stain to even out the boards, which is what the large-scale professionals do (Thos. Moser talked doing that staining years ago)? Again, looking for low-sheen/matte, and I can't spray something this big. Heck, I have to finish the panels separately, then take them up to the bedroom to assemble since this queen-sized Murphy Bed is so big.

 

[kevinculle]

Do the rough cuts for your project and use the scraps of plywood and solid cherry to work out a finishing schedule that best matches to two.  Sand the scraps as you intend to sand the project before finishing then give one set of each the same finishing schedule as a baseline and see how the appearance differs.  Then experiment with basecoats, tintng, etc. until you are satisfied.  It's good to be systematic and mark all your samples so you know what's what.

 

[smorgasbord]

...work out a finishing schedule that best matches...

Sure, but what I hoping is to get somme advice so that the ones I try have a higher chance of success than just me trying out different things....  Especially on the sanding side, as I've seen that differences in sanding of the same wood can result in different appearances when finished. So with the plywood being pre-sanded, one of my concerns is how to work off of that to have the same level of sanding in my solid wood pieces. Hopefully, the finish matters less, although I do expect some finishes to be more sensitive to this than others. And going low-sheen/matte may help, too.

 

[Crazyraceguy]

In general, solid wood and veneer will take stain differently. Sometimes sanding them to different grit can help blur this line some, but that is not always an opiton

 

[smorgasbord]

Yeah, I am worried about ply and solid taking the finish differently. I've decided not to use a stain. My leading contender is Odie's Oil, maybe the Dark version, but I also have the normal to try.

I've not dealt with plywood in a long time. This is A1 graded stuff - should I assume I can start with 180 grit and take it from there? Odie's recommends sanding to something like 320/400 grit. I'm not intending to use my random orbit sander on the play - either just hand sanding or maybe try out the LS 130. I'm really parnoid about sanding through the thin veneer on today's plywood.

For the solid wood, I'll probably end up hand scraping the planer marks off, and then a sanding regimen starting in the 150-180 range.

Any thoughts on what sanding procedures I should use are most appreciated.

 

[Tom the Remodeler]

My response will be adjacent to your project, so take from it what you will.... :

I'm currently working on installing the ceiling in my Shop. The insulation is batts in the joist bays, with a layer of foil-faced poly-iso beneath, taped to the framing members to produce a vapor barrier. The finished ceiling material is 12mm VC White Birch C-2 plywood, ripped to 8' x 400mm strips, installed in a staggered pattern, with 6mm gaps between the panels. It's a cool look, and I'm inclined to implement a variation on it on the walls.

In terms of finish, I opted for Rubio 2C in "Super White". I've personally found that the hw oils don't apply well if the wood is sanded above 120. After some testing, I determined that I got a preferred finish doing the following:
-- Sand the surface with a Mirka 230mm sander at 120
-- Wipe the surface with a damp microfiber cloth. This removes the wood dust, and "pops" the wood fibers to better accept the oil
-- Let panel sit for a few minutes for the water to evaporate (I keep my shop around 25% RH, so evaporation is pretty quick)
-- Apply a pre-measured amount of Rubio to the panel
-- Trowel the oil (~1.5 ounces will cover a 16" x 8' panel) around with a 6" putty knife to mostly cover the surface
-- Use a Oreck Orbiterhttps://www.acmetools.com/oreck-commercial-orbiter-orb550mc/743808005500.html with a Red pad to mechanically work the oil into the surface
-- Let the oil set for a couple minutes (I often use this time to apply oil to another board)
-- Remove any excess oil (there should be almost none) using the Oreck Orbiter and a White pad
-- Wrap a blue paper shop towel around a neoprene block (to avoid pressure/"hot" spots) and wipe the surface down with the grain until the towel comes up dry
-- Set the panels aside, they're ready to be installed next day

I'd suggest pre-finishing as much as possible prior to assembly. The plywood will likely appear different than the solid wood, no good way around it, but the colors should mellow and blend over time......