Sanding question, and more...

For those that haven't been following my saga, I'm a newbie taking an adult ed class. I've chosen to make a bookcase for my project.
So I have all of my pieces cut to size and am ready to put it all together. I plan on using woodscrews to attach the pieces. I'm also planning on "sinking the screw head into a larger hole" (not sure what to call that) cut with a forstener bit and cutting my own plugs to fill in the hole. So now on to the questions...
1) What size forstener bit should I use (knowing I need to match the plug cutter)? Most of the panels are 3/4" x 10.5" x differing lengths.
2) How deep should I cut the forstener "hole"?
3) Sanding - should I sand all my pieces before attaching the pieces with the screws? I ask because I know I'm going to have some additional sanding after cutting the plugs off in the screw holes. So do I sand everything first and then just re-sand the plug areas? Or do I wait and not sand until the plugs are in?
If it makes any difference, I'm going to need to do some evening on the panels I glued together (there is a little variation here and there that I need to make flat) - either with heaving sanding or trying to hand plane to flat.
Thanks for the advice.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

a good place to start.

countersinking.
3/8" and 1/2" are common plug cutter sizes. get the plug cutter first. make some plugs and choose the drill bit to fit the plugs. you don't have to use a forstner bit, though if you happen to get a good size match that will be a nice way to go. regular old twist drills are commonly available in 1/64" increments though, should you need to bump up or down a tad.
whatever tools you end up using, do a mock up of the whole joint and make sure it's all going to go together well before you make any holes in the actual project.

not more than 1/3 of the thickness of the board, and not less than you need to be able to glue in the plug.

I try to do as much sanding as possible before assembly. there will always be some sanding to do after assembly, but it's sure easier to do flat....

sounds like a good opportunity to learn to use a card scraper.

thanks for playing.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Another method to consider is pocket holes. Essentially, the guide used makes the process a two-part operation -- drilling the small hole for the screw to pass through and a larger but shorter hole (partially into the wood section) to take the screwhead below the wood surface. Yes, that's called a countersink.
Screws go in at an angle, which gives them a bigger bite and more leverage for a clamping action.
Anyway, check out Lee Valley Tools (based in Toronto Ontario) at their website http://www.leevalley.com and enter pocket hole as the search term. You should be looking at a half-dozen guides, drill bits as well as hole plugs. Prices are in Canadian dollars, which convert to about $.75US.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Now don't go leading Corey astray at this point. He's three weeks into his first, 5-week adult-ed woodworking class, and his friends here have already filled his head full of semi-useless knowledge. ;-)
When he goes to his first woodworking show, THEN he'll find out how many ways there are to put two pieces of wood together. And how many ways to max out the credit card.
Patriarch, who just built a nice garage cabinet, using the best pocket screw technology.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The pneumatic thingy?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

McFeeley's screws. The pneumatic thingy, the one that puts in the brads 'until the glue dries', didn't get used this time.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Don't rule out rebated lap joints or dadoes. Screws are strong, but they're not very rigid. In a class you should be able to improve things with only a little effort.

Counterboring.
Forstner bit is the wrong tool. It's hard to find them that small and they cut badly. You may also find that it's easier to locate a drill with a central pilot.
I'd buy a pair of commercial bits (Lee Valley) - one cuts a screw hole and counterbore, the other cuts a matching plug.

1/4" is plenty for the plug, plus the depth of the screwhead. If the drill has a shallow angle, then much of this depth will be a countersink.

Yes, because it's easier when they're flat. Then sand them again after assembly. You might just go to your first grit for the first "flat" pass.
Unlike planing, sanding an already-sanded surface is easier than an unsanded one.
--
Smert' spamionam

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have several different brands that are labeled Forstner and they all have pilot points, although I have seen some that do not.(maybe the "originals") If your Fostners are cutting badly they must be dull, I get a nearly perfect clean hole with mine.
Dennis
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Tiny little spear points though, which will have almost no effect when trying to start a hole over an existing clearance hole. A twist drill with a full cone in the centre, or a dedicated screw sinking bit with a sized pilot, will be easier to guide.
If you have a drillpress, then you can probably use these Forstners perfectly well. If you're drilling by hand, then it's likely to skid right across the surface, the edge of the Forstner acting like a wheel.

Forstners have a large solid area, and in these small sizes that doesn't allow space for chip clearance. I'm guessing the OP is working in softwood here and shifting those chips might be a problem.
--
Smert' spamionam

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Or veneer. The steaming and peeling, not to mention the micro thinness of modern ply tends to chew at first bite.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 09 Oct 2004 11:52:38 +0100, Andy Dingley

if I'm visualizing his project correctly, I's suggest both a forstner and countersink/drill combo... the forstner would provide a nice flat bottomed hole to make the plug gluing easier, but you need the tapered countersink/counterbore for the screw head to seat properly, right?
I always use the forstner 1st, to start the hole, then follow with the normal or combo drill, using the forstner's spur hole to start the drill.. YMMV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

You might do this if you were using a large plug and a small screwhead. It's easier though just to drill and pluge in one pass - the sizes are usually OK

Only if you care what it looks like. Down the bottom of a hole, the screw will seat fine and you'll never see any gap or broken fibres around the edge..
Particularly in softwood, you don't need to countersink either. There's a Stanley combination drill (taping, clearance and head) which forms a neatly set screwhead by scribing a circle around it, rather than countersinking. The countersink is formed by compression alone, but the scribed circle forms a neat edge.
--
Smert' spamionam

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 09 Oct 2004 19:43:23 +0100, Andy Dingley
<snip>

Thanks, Andy.. I'd always understood that the countersink/bore was (in addition to making it flush in a surface), let the screw be tightened without cracking the wood... (I use the B&D drill/stop/countersink bits)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Andy Dingley"

You mean the hundreds of countersunk and plugged holes I've done are wrong? I chose Forster bit because they cut so well and the ones I have do have a central pilot. (see Lee Valley)
Many ways to accomplish the task but I want as perfect a fit I can get. I mark the holes and drill a 3/8" dia. hole about 3/8" deep with the Forstner bit. The Forstners also have a point so locating the bit to the mark is easy and accurate. Then I use a twist drill or a drill with countersink to make a pilot hole. After sinking the screw, I can plug the holes with tapered plugs for a very nice finish. The drilling can be done in one step but I like the control of doing the countersink on the drill press. I'm not running a production shop so a few extra minutes if OK.
The tapered plug cutters from Lee Valley do a good job. There is a saw made for trimming plugs and then just sand or plane as you see fit.
On some projects, like a pine kids picnic table, I used dowels instead of plugs. They have end grain showing and are not as attractive as plugs, IMO, but they work. Done right, they look pretty good with the contrast of woods when finished. Ed
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would pass them through a planer if available until all are of the same thickness - regardless of whether they need it or not.
That is, all shelves should be equal in thickness to look ok.
You mean only screws will be holding up the shelves? If so, use at least 4 screws per side if they are to hold books. Next time, let them in (dado).
Lou
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What you will be doing is counter sinking the screw heads. A fosner bit is the long way around. You can get sets of drill bits and matching plug cutters that will do the job nicely for you. Then all you have to worry about is the size of the screw. I like #8's Robertson screws (square drive) for general usage.
It wouldn't be a bad idea to get the heavy sanding out of the way before assembly then all you have to do is some clean up sanding when you are done.
Good luck.
--
MikeG
Heirloom Woods
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Glad to see you're still going strong on this, Corey.
The answers the others have offered look pretty good to me. Follow their advice. Keep smiling. And have fun with this.
There are all kinds of adventures in front of you yet.
Patriarch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.