sub frames for not deep enough frames.
Posted: Sat 11 Jul, 2020 10:54 am
Obviously, there is not much point in making up your own sub frame mouldings, when you can buy perfecyly adequate sub frames moulding straight off the shelf from our existing suppliers at a very reasonable cost. However, what do you do when a customer wants something large framed in a very small narrow moulding, with out much depth to place a sub frame at the rear of the frame?
Well, one possible solution is to use a bit deeper frame and cut a little bit off each face of a standard off the self sub frame moulding using a table saw, it may not always be the perfect solution, for every case, because there is only so much you can remove without weakening the sub frame moulding and making the whole exercise a waste of time, but may be a practical solution in some situations.
In more extreme situations, you will not be able to cut down the thickness of a standard sub frame moulding without getting so close to the groove which is intended for placing the fixing screws from creating severe loss of strength, and rendering this solution as unworkable. So in such cases, another solution may be needed! The problem is largely due to the presence of the groove for the fixing screws!
Fortunately, you can drill holes with a pocket hole jig and screw the sub frame into position by similar means, but there may still be a problem! The screws for a pocket hole jig, may be a bit too large for the space available. In cases like this, you can part drill the pilot hole, using the narrowest first part of the pocket hole jig to make a hole at a good starting angle to line up a small " screwsinker" type of self counter boring drill and then insert a suitable, but smaller diameter screw.
Take care not to over tighten the screws and end up slitting the wood. Pocket hole jigs are usually intended for use in wood above a certain thickness, so a packing piece may be required to reposition the wood you are drilling, so that the screw emerges in the right position. As you may have already guessed, there are limits to how thin the wood can be to produce a usable result, and also how thin the wood can be to provide any worthwhile strengthening effect in supporting the inadequate strength of the frame. This is just one suggestion, maybe others have other suggestions as well!
Well, one possible solution is to use a bit deeper frame and cut a little bit off each face of a standard off the self sub frame moulding using a table saw, it may not always be the perfect solution, for every case, because there is only so much you can remove without weakening the sub frame moulding and making the whole exercise a waste of time, but may be a practical solution in some situations.
In more extreme situations, you will not be able to cut down the thickness of a standard sub frame moulding without getting so close to the groove which is intended for placing the fixing screws from creating severe loss of strength, and rendering this solution as unworkable. So in such cases, another solution may be needed! The problem is largely due to the presence of the groove for the fixing screws!
Fortunately, you can drill holes with a pocket hole jig and screw the sub frame into position by similar means, but there may still be a problem! The screws for a pocket hole jig, may be a bit too large for the space available. In cases like this, you can part drill the pilot hole, using the narrowest first part of the pocket hole jig to make a hole at a good starting angle to line up a small " screwsinker" type of self counter boring drill and then insert a suitable, but smaller diameter screw.
Take care not to over tighten the screws and end up slitting the wood. Pocket hole jigs are usually intended for use in wood above a certain thickness, so a packing piece may be required to reposition the wood you are drilling, so that the screw emerges in the right position. As you may have already guessed, there are limits to how thin the wood can be to produce a usable result, and also how thin the wood can be to provide any worthwhile strengthening effect in supporting the inadequate strength of the frame. This is just one suggestion, maybe others have other suggestions as well!