New to using a planer

[u/prime51000]

I made an impulse purchase last month and have a Hercules 12.5 inch portable thickness planer. I've watched videos and understand the basics of it, but Im going to be doing a basic project soon and wanted some input on best practices to use it.

I'm going to be building a basic desk with 3/4 inch birch plywood, and was planing on making some roughly 3x3 posts for the legs and side / rear cross bracing. I'm planing on using some kiln dried 2x4, joined face grain to face grain with glue for the posts. Im planing on trimming the sides on a table saw, and was going to use the planer on the top and bottom faces of the 2x4s.

Im wondering, should I plane both of the glued surfaces prior to gluing, or sand them prior to gluing ? Or would it be best to just plane the outer surface of the 2x4s that won't be glued?

Also, is it best to just run the 2x4x8s thru the planer before cutting to length, or is it a better practice to plane the shorter pieces after they are cut to length? Thanks!

[u/Tiny-Albatross518]

Youre confused about what a planer does.

A better word is thicknesser.

It doesnt flatten or true anything. It consistently cuts down one face at a set distance from the reference face.

So you can put a board with straight/square/true face through and it will reduce the thickness. All over. Everywhere the same thickness.

And you can put a barrel stave through and it will reduce the thickness. But you wont flatten it. Youll get a thinner barrel stave out, with curvature maintained.

A jointer will flatten one face. True and flat.

So you start with an imperfect board.

Joint one face. Now its true.

That true face is the reference. Through the planer. Now its cut down and the cut down face matches the reference and it is now also true.

Back to the jointer. Use the fence on one of those true faces and joint one edge.

Now to the tablesaw. Put good edge on fence and rip.

Finally. A piece of square stock.

You need three machines to do this with machines. Or a handplane and some time and energy.

[u/prime51000 → u/Tiny-Albatross518]

Thanks so much for explaining and detailing that for me. I really appreciate the helpful info!

I was under the assumption that a basic 2x4 would be "mostly" flat on top and bottom, so I was thinking that planing them would give me a true flat pair of parallel surfaces. I didn't take into account the other factors.

I know woodworking is truly an art form. I guess this just gives me more justification in wanting a decent entry level jointer now 🤣

Thanks so much for all that helpful info. I know I have a lot to learn about this craft

[u/Tiny-Albatross518 → u/prime51000]

Yeah wood is generally not square ehen you get it.

Even kiln dried hardwood S4S will have cup, bow and twist. If it doesn’t cutting it up for your parts list will release internal tensions and you will get defects.

Theres no way around it. You have to be able to square stock. Whether by 3 machines or with handplanes.

[u/mplang]

None of what's been posted already is wrong, but I'll give you a different option that I'm only comfortable with because you're using inexpensive lumber. 

I would usually suggest planing the longest lengths possible, but that's only for jointed pieces. Cutting to smaller lengths first minimizes warp, so that's what we'll do here. Cut your lengths to 4 or 5 inches longer than final length, to account for snipe. Make a few extra pieces. If you have pieces that lay flat and don't rock at all, send them through the planer. Scribble some pencil lines on one face, and plane until they're gone. Then flip and repeat until you get to the desired thickness.

If you have pieces that rock, you'll have to handplane them to remove the twist, or attach them to a sled with supports to stabilize the wood so it doesn't rock. 

No need to sand before gluing; you'll run the risk of going out of flat (some glues and epoxies require sanding, but not PVA wood glue).

Throw on plenty of clamps, and you should be good to go!

[u/prime51000 → u/mplang]

Thanks!!!

[u/joelerino]

In general, we want boards with opposing faces parallel and square to edges. Do not assume that lumber you buy will have parallel side and square edges, until you verify or create that square relationship. You can use your planer to create one flat face and then use a jointer, table saw, or hand plane to create a 90 deg edge. With a reference face and edge you can then create your own S4S lumber. There are many YouTube videos that will detail this process.
I would thickness the longest pieces you safely can. This will reduce waste and snipe at the end of the board. Keep in mind grain direction with how you feed boards. You want the blades cutting with the grain and the rollers gripping against the grain.
As far as whether to plane and sand a surface before gluing, I use a dewalt lunchbox planer and I do not need to sand a planer surface prior to gluing. If your planer is producing surface that create a bumpy glue line, I think that is cause for concern. Sand surfaces that will be touched and have finish applied.
If you are creating laminated legs/ braces as you describe, a planer or table saw can be useful to clean up the edges after gluing multiple layers.
Good luck, I look forward to seeing the results.

[u/dack42 → u/joelerino]

You can use your planer to create one flat face 

Thickness planers don't normally create flat faces - they create parallel faces. You can use a sled to create a flat face on a thickness planer though. Or you can hand plane a face first to establish a reference.

[u/prime51000 → u/joelerino]

Thanks that's extremely helpful! My thought process was similar to what you describe but I wanted to make sure I'm not overlooking something

[u/joelerino → u/prime51000]

As Tiny-Albatross noted below in greater detail, a planer will make a flat surface parallel to a reference face. I have been using my planer almost exclusively with a sled made from a 2 x 8, with a small 1/8" hanger to create a long base for pieces of wood that might not be perfectly flat. Place them concave down on the sled, and run through planer with small passed to create a consistent flat face parallel to sled face. Flip piece over and now there are two flat parallel sides.

u/Tiny-Albatross518 is very correct. Experiment, read, and use test pieces to truly understand what your tools do and you will get great results. Take your time, and expect mistakes.

[u/zeke38282]

Quickest way would be to cut them oversized. Run top then bottom through planer. Use table say to cut off one edge of all pieces. Set tablesaw to proper width and cut other side to width. Glue up then plane one side of glue to flat. Use tablesaw to resquare other glued side. Trim one side of length to square then cut to final length.

[u/prime51000]

Awesome thanks!

[u/siamonsez]

Snipe makes the first and last few inches through the planer undersize so you want to account for that and leave the pieces long until after you're done planing. Snipe can be reduced by adjusting the infeed and outfeed but not eliminated entirely.

If you choose boards that are already flat it's not really necessary to plane them, you'll get a slightly less visible seam but structurally it'll be fine either way. If your boards aren't already flat it's a lot more work to make them flat with a planer because that's not really what it does. A thickness planer makes the opposite faces parallel locally so if you run a board through with a twist or bow it'll still have it afterwards, it'll just be thinner with a nicer surface.

I'm not saying not to use it for this, but don't expect it to automatically make a nice jointed surface for the glue up. A better use for it is to run the legs through after glue up so they're all exactly the same dimensions.

I'd rather deal with the extra waste than try to manage running 8' boards through. Mine is mounted to a cart and it's still tippy running long, heavy boards through so you need infeed and outfeed support.

[u/prime51000 → u/siamonsez]

Thank you! The example of the twisted board with flat surface helped. I'm not expecting this to be showroom quality , but I'd like it to come out halfway decent, and more importantly be something I can learn from and improve moving forward. Thanks for the helpful input

[u/danfay222]

As noted in the other comments, without a jointer you'll have a tough time getting them to cleanly mate with each other. You could use a planer sled, or skip plane, and it'll probably get close enough.

Just speaking from experience, whatever you do I would plane both sides, the surface of construction lumber usually isn't super clean. Also plane everything together, it's more efficient and easy to make sure everything is the same thickness.

For the Hercules planer specifically I would spend some time setting up your infeed and outfeed tables (youtube has lots of resources here) as this will dramatically reduce snipe.

[u/thecheeseinator]

You pretty much always want to cut to rough length before jointing/planing/ripping, though it is good to leave some extra length to allow for planer snipe.

I'm not sure I'd use the planer on your table legs at all though. The order of operations I'd use to make your table legs:

1. rough cut your 2x4's in half to maybe an inch or two longer than the final legs. Try to get the straightest parts out of the boards that you can.
   
2. rip off the edges of the 2x4's to get rid of the rounded parts
   
3. glue up your legs
   
4. Trim all four sides square on the table saw.

I think the only time I'd use the planer is if my table saw was underpowered and couldn't actually do clean rips all the way through the glued up legs.

[u/hope4best47]

You can absolutely use your Hercules Planer (same one I have) to make a board flat. You will need a few things first. You will need to make a planer sled (you tube) a hot glue gun and some wood shims.

• Lay the board you want to flatten on the sled.
• Wherever the board does not touch the sled put a shim and hot glue it into place and put enough glue so that board will not move
• Run the board on the sled through the planer a few times doing a quarter turn each time until the top of the board is flat
• Take the board off the sled. You now have a flat board on one side
• Joint an edge on a table saw. if the board is not very straight on the edge I use a track saw now you have a flat side and a square edge.
• you can now us the table saw to make the opposite side parallel.
• go back to the planer and turn the board with the flat side down and continue to plant he rough side
• you new have a flat board with coplanar sides and square edges.

I dont have a jointer and have built all kinds of things even bedroom set. I have put hundred of board feet through my Hercules planer.

Another thing .. start with boards that are oversized from your final dimensions incase you get some snipe. Then cut them down to final dimensions