Sanding Hardwood Plywood

[Steven Owen]

I’m going to have some projects coming-up next year that will require he use of hardwood plywood.  What are some of your reccomendations for sanding techniques with hardwood plywood for a stained, dyed surface with a laquer or varnish top coat?

Your dealing with a thin veneer.  The biggest mistake you want to avoid is damaging/thinning out the first layer of the veneer.

 

[semenza]

  I have narrowed it down to one thorough pass with 180 grit. Once in a while 220. But that's all it really needs.  Have used both 3mm and 5mm stroke random orbit sanders. The veneer is very thin but doesn't really need much sanding. I have never gone through unless really overdoing trying to even up a solid edge band or something.

  If talking true baltic birch  , that is usually a bit rougher to start and then I do 150 followed by 180.

Seth

 

[Holmz]

The optimal may be a belt sander with a frame for controlling the depth.
I have some 240, 320, and 400 belts coming, so I am not speaking from a lot of experience... yet.

A 1/2-sheet is good for spreading out to a large footprint - so that the surface stays flat.
I have one that works like a champ, but it takes 60% longer than a 6" random orbital - even though it has the same watts.
I usually also move it in the grain direction out of habit.

For only just smoothing it, then a 6" random is good with ~180 or 240.

Which ever way one goes, a kiss with a Mirka or Festool hand block 'inline with the grain' is what I commonly do... mainly out of habit.

 

[McNally Family]

[member=40772]Holmz[/member]

When I wanted to hang a few sheets of plywood to hang tools on, and  practice my finishing at the same time, I used the Festool RS2 with a finer sandpaper, then the Festool hand sanding blocks, which (as Holmz pointed out), work particularly well between coats.  The extremely flexible Festool HSK D21.5 hose that attaches to the hand sanding block make this process a breeze. 

For my practice finish, I used about 3 coats of WATERLOX (take ventilation seriously with this product).  The results are certainly extreme for plywood that is hanging in a basement workshop, but you practice wherever and whenever the opportunity presents itself.

 

[Pnw painter]

For stain prep I'll use my ETS EC 150 with 150 or 180 grit.

Many of the high-quality plywoods come pre-sanded from the factory, so they shouldn't need much prep. Side lighting the plywood can help you spot any areas that may need extra sanding.

Festool's new foam backed hand sanding abrasives would also be a good choice for this type of project. Not many dealers carry them, but after using them on several recent projects I've fallen in love with them.

Sent from my iPhone using Tapatalk

 

[Holmz]

[member=60452]McNally Family[/member] I use the Mirka block in the 230x115 mm size and more commonly the smaller 3"x8" size. The littler one is about the same width as the 25M rolls of abraidnet at $25/roll... so I cut a sheet worth off the roll and it is 20 cents/sheet. And it lasts ages.

The Festool is conceptually the same. so it is a lemon versus lime in color.

The large one takes the same sheets as the 1/2 sander, which is slightly different from the RS2, so I think the FT might take the same sheets as their large hand pad? Does it take screens or papers?
The main advantage of the screens is that finishes that load a paper require removal of the screen and a shake out... Then back on with the used screen for more work.

Often the plywood is so good it just take the "kissing of the hand block" and no power tool.

 

[junk731]

Hardwood plywood covers a lot of possibilities and depending on source can be good to extremely poor. This can vary day to day even within the lift and supplier. It has a tendency in general to show an inconsistency in surface appearance under a raking light. This is due to the crap cores most are using. Personally I use plywood for building boxes wear the surfaces aren't seen and lighter weight is needed. I use PC, FX or MDF core for projects where flat is important. The inconsistency in the surface in hardwood ply makes burn through easier especially using a sander that covers a larger surface area as they have a tendency to hit the high spots more. ETS 150 with the regular pad works OK with 150/180 grit. Watch block sanding with Mirka abranet, in some situations you can get grid lines because of the way the paper in made.

John

 

[sancho57]

My only concern for sanding ply is sand through the veneer. One other thing you might want to consider is the plys core. Depending on what your plannig on doing with the ply. If you need perfectly flat ply for the application think a MDF core ply. They make a combo core ( forget the actual name) that has the layers of ply with a center of MDF they are usually flatter then reg core ply.

Saves ya sanding time to. If your not planning on staining the ply you can spend a little bit more money and buy is refinished.

as my man Sedge says " I hope this helps"

 

[semenza]

Personally I think that a belt sander , even with depth control frame, is just asking to sand through the veneer.

In general it just doesn't need much sanding.

Seth

 

[Steven Owen]

Personally I think that a belt sander , even with depth control frame, is just asking to sand through the veneer.

In general it just doesn't need much sanding.

Seth

I’d also think increase caution in handling and storing the plywood plays Big roll too.  I was thinking of keeping a roll of thin packing styrofoam to protect the sheets to prevent adding problems and scratches through mishandling.

If I plan to make a side business building wall mounted TV stands, I have to consider clever ways of reducing the weight for wall mounting to make the stand easier to lift and mount.  A combination of solid hardwood top and Hardwood plywood seems the way to go. 

I wonder how restistant an MDF core would be to warping under wieght.  High end audio equipment can add 250-400 lbs to a stand depending the set-up. MDF on it’s own can warp when a heavy load is not balanced well.  You see MDF warps in around the lift system Router tables all the time when the MDF cannot be reinforced.

 

[J0hn]

Half sheet sander with 180 grit. I have a Bosch that works great, good dust collection and covers a large surface area with good speed. Simple and the paper is cheap, I just buy Klingspor sheets in bulk.

Yep - one of the reasons why I bought the Bosch 1/2 sheet sander recently. https://www.amazon.com/Bosch-OS50VC...F8&qid=1511290062&sr=8-2-fkmr1&keywords=bosch+half+sheet

[attachimg=1]

 

[Steven Owen]

Half sheet sander with 180 grit. I have a Bosch that works great, good dust collection and covers a large surface area with good speed. Simple and the paper is cheap, I just buy Klingspor sheets in bulk.

Yep - one of the reasons why I bought the Bosch 1/2 sheet sander recently. https://www.amazon.com/Bosch-OS50VC...F8&qid=1511290062&sr=8-2-fkmr1&keywords=bosch+half+sheet

[attachimg=1]

I’m surprised how expensive the OS50VC is for Bosch sheet sander.  $539 Canadian.  Usually most Bosch’s are cheaper.

 

[J0hn]

Ouch

I looked up the exchange rate and $539 Canadian is $421 U.S.!

 

[McNally Family]

Ouch

I looked up the exchange rate and $539 Canadian is $421 U.S.!

Last time I looked the Festool RS 2E was $410.00 US.

 

[Steven Owen]

Ouch

I looked up the exchange rate and $539 Canadian is $421 U.S.!

Last time I looked the Festool RS 2E was $410.00 US.

$580 Canadian.  The Bosch is only $40 cheaper.  Amazon Canada is on some serious dope.  Look at Canuck tool.

 

[Holmz]

Personally I think that a belt sander , even with depth control frame, is just asking to sand through the veneer.

In general it just doesn't need much sanding.

Seth

It does seem counter intuitive.
Which is where some factual evidence is worthwhile. (which I do not have).

However there are belt made up to at least 1000, and the sanding is linear.

I would grab the belt sander before considering an RO-# sander, but I do need to get the frame still.
I threw it out there so people with experience could weight in, and plywood is generally flat so it is different than a slab of wood for a table.

The last time I used a framed bet sander was 25 years ago and on oak it still took all day.
It is only fast when you make a mistake  [big grin]

 

[Holmz]

Ouch

I looked up the exchange rate and $539 Canadian is $421 U.S.!

Last time I looked the Festool RS 2E was $410.00 US.

$580 Canadian.  The Bosch is only $40 cheaper.  Amazon Canada is on some serious dope.  Look at Canuck tool.

So we can ignoring the cost then...
Which one is better? (How and why)

 

[J0hn]

In the US - there is an $80 difference in price between the Bosch and the Festool.

BUT - don't forget that Bosch doesn't illegally 'Fix the Price' (for which Festool was fined ~$7 million in Europe)  Bosch has a current promotion for $30 off 

Here are the reviews on Amazon - I am very happy with the Bosch

[attachimg=1]

 

[Steven Owen]

In the US - there is an $80 difference in price between the Bosch and the Festool.

BUT - don't forget that Bosch doesn't illegally 'Fix the Price' (for which Festool was fined ~$7 million in Europe)  Bosch has a current promotion for $30 off 

Here are the reviews on Amazon - I am very happy with the Bosch

[attachimg=1]

If the cost difference was only at the exchange rate, Canadians should be paying $430 - $450.  We get screwed on duties and border taxes making it $530 Canadian.

Let’s not digress, the Bosch OS50VC looks a like a good option for hardwood  sheet sanding.  It has a more modern anti-vibration system.

 

[Holmz]

In the US...

Does the Bosch have the Velcro on the base?
Amazon and others sell the abraident in 230x115 (which my 1/2-sheet takes).

At the end of the day he sander just wriggles the paper, so there is not much to say other than orbit size, rpm, power and vibration.
But a good 1/2-sheet is still a pleasure to use.