|Home » Forums » Architectural Woodworking » Message||Login|
You are not logged in. Consider these WOODWEB Member advantages:
Sanding double hung sashes4/19/15
Because the meeting rail is thicker or taller on double hung window sashes I can't run them throug the wide belt sander and thusly sand them by hand which I loathe to do. Looking for a better strategy. I've done an applied piece after they're sanded and don't much care for it either.
If you are making them leave the meeting rail off, run them through the sander and then glue the rail on. Only works if it's a dado, not a mortise and tenon.
It is possible to dry fit mortise and tenoned work together and send thru a wide belt.
I once spent a few years making 3/4" thick interior louver and shutter panels. The moveable slat louvers were all dry fit without slats and pushrods, sent thru the sander, and then taken apart and glued together with the slats in place. Then sanded with a pad sander.
When we (rarely) did DH window sash, we just did not sand the side that had the protruding lock rail, and used a carried to hold the other side flat. We even fitted the muntins in the sashes, and hoped they would make it thru to the other end intact.
We wide belt sand all our window parts and most door parts before machining then do a light orbital sand after assembly to flush joints and get rid of glue and marks from machining.
The S4S, tenoning and profiling must be accurate to within 0.2 mm or so (about .001") to do this. The wood movement is going to cause that much variation.
We have found this is easier than sanding out crossgrain scratches from the WBS.
I completely support pre-sanding with a wide belt, any parts before assembly. Done correctly, this will introduce a scratch pattern that will open up the surface and give something to sand off. Hand sanding should only be to remove the scratch without grinding too much off. This will give the best surface and the least swirls.
Orbital sanding molded or planed wood to finish is notoriously inconsistent and very unforgiving.
I used to make sashes and I would sand the check rail side separately and then use a piece of 3/4 particle board under the sash so I could use the wide belt with the check rail side face down. At least you can sand one side put together.