Underpinner problems
- Thread starter Banjo
- Start date
D
Dermot
Guest
Banjo
Which wedges are you using hardwood or softwood, for most of the mouldings in this part of the world softwood wedges should be ok.
BTW which underpinner have you got!!!
Regds
Dermot
PS
I will get that box of stuff away to you this week, sorry for the delay, I’m under huge pressure at present……family sort things….bottom line is I haven’t forgotten you.
Which wedges are you using hardwood or softwood, for most of the mouldings in this part of the world softwood wedges should be ok.
BTW which underpinner have you got!!!
Regds
Dermot
PS
I will get that box of stuff away to you this week, sorry for the delay, I’m under huge pressure at present……family sort things….bottom line is I haven’t forgotten you.
Bill Henry-
Brussel Sprout Connoisseur
Regardless of how thin the V-nails are, they will tend to separate your mouldings somewhat. Hard woods will separate more than will soft woods.
When we first got our hand operated joiner (a Pistorious VN-J) we struggled for months with oak mouldings which never seemed to have perfect joins. We finally decided for those mouldings we would have to go back to the standard right angle vice and straight brads.
But the problem you observe may not be solely due to your joiner; it may have to do with the mitering system you’re using. After several months of using a miter saw, we discovered that the back fence was not truly perpendicular to the table itself. To compensate, we wedged a razor blade beneath the bolt which held the fence to the table making the angle a fraction less than ninety degrees. That solved that problem and our joins were a whole lot better.
It would, of course, be a lot more difficult if not impossible (and probably unnecessary) to do that with a chopper.
When we first got our hand operated joiner (a Pistorious VN-J) we struggled for months with oak mouldings which never seemed to have perfect joins. We finally decided for those mouldings we would have to go back to the standard right angle vice and straight brads.
But the problem you observe may not be solely due to your joiner; it may have to do with the mitering system you’re using. After several months of using a miter saw, we discovered that the back fence was not truly perpendicular to the table itself. To compensate, we wedged a razor blade beneath the bolt which held the fence to the table making the angle a fraction less than ninety degrees. That solved that problem and our joins were a whole lot better.
It would, of course, be a lot more difficult if not impossible (and probably unnecessary) to do that with a chopper.
psychoframer
True Grumbler
You might want to try a search of the archives, I know this topic was recently discussed.
Good Luck,
Tom
Good Luck,
Tom
Framerguy
PFG, Picture Framing God
If your mitered joint will lay on a flat surface with absolutely no gap in it, and you are experiencing a slight gap on the top (and not the "point") of the miter, then it may be that your driver and the vee-nail is reaching the base of the wood joint a fraction before the hold down reaches the top of the wood joint. If that hold down isn't firmly against the miter before the vee-nail starts its entry into the wood, it could lift the miter a fraction off the surface of the underpinner and cause a slight gap on the top of the miter joint.
It is hard to check on a pneumatic nailer but on a manual nailer you can have someone watch as you slowly operate the nailer and check the contact of the hold down and the relationship of it to the position of the vee-nail at that point in time when the hold down just makes contact with the wood.
FGII
Now, if you are getting a gap on the lower portion of the outside "point" of your miter joint, that is an entirely different problem.
It is hard to check on a pneumatic nailer but on a manual nailer you can have someone watch as you slowly operate the nailer and check the contact of the hold down and the relationship of it to the position of the vee-nail at that point in time when the hold down just makes contact with the wood.
FGII
Now, if you are getting a gap on the lower portion of the outside "point" of your miter joint, that is an entirely different problem.
Banjo:
The first task is to isolate the problem. You seem confident that the v-nailer is the cause, but are you sure? Is this always a problem, or only with certain mouldings, or certain kinds of wood, or certain shapes? Have you experienced the problem with miters cut on other machines, such as frames chopped by your suppliers? How long has it been going on?
As a general rule, any movement of the moulding during cutting or joining results in an imperfect joint. So, you could have a perfect miter and experience v-nailer troubles, or the opposite -- the v-nailer may be working on slightly imperfect miters. Results might look the same either way.
Sometimes, as our chopper knives begin to dull, we get the problem you describe. When we cut the first miter (right end of stick), the moulding is pushed slightly to the left, making the miter slope toward the right as the knife goes down. That means slightly more wood was removed at the top of the cut, making a gap at the top of the joined corner. FIX: Install sharpened knives and hold the moulding firmly in place during the first cut.
The position of the v-nailer's holding devices is important, but I don't know whether this would apply to your Morso. On our Amp/Miter-Mite/Putnam VN42, the miter's top may open if the upper hold-down is placed slightly behind or in front of where the v-nail enters the bottom. When the v-nail is driven, the moulding pieces are twisted one way or the other, opening either the top or bottom of the miter. FIX: Reposition holding devices to equalize upward and downward forces.
The first task is to isolate the problem. You seem confident that the v-nailer is the cause, but are you sure? Is this always a problem, or only with certain mouldings, or certain kinds of wood, or certain shapes? Have you experienced the problem with miters cut on other machines, such as frames chopped by your suppliers? How long has it been going on?
As a general rule, any movement of the moulding during cutting or joining results in an imperfect joint. So, you could have a perfect miter and experience v-nailer troubles, or the opposite -- the v-nailer may be working on slightly imperfect miters. Results might look the same either way.
Sometimes, as our chopper knives begin to dull, we get the problem you describe. When we cut the first miter (right end of stick), the moulding is pushed slightly to the left, making the miter slope toward the right as the knife goes down. That means slightly more wood was removed at the top of the cut, making a gap at the top of the joined corner. FIX: Install sharpened knives and hold the moulding firmly in place during the first cut.
The position of the v-nailer's holding devices is important, but I don't know whether this would apply to your Morso. On our Amp/Miter-Mite/Putnam VN42, the miter's top may open if the upper hold-down is placed slightly behind or in front of where the v-nail enters the bottom. When the v-nail is driven, the moulding pieces are twisted one way or the other, opening either the top or bottom of the miter. FIX: Reposition holding devices to equalize upward and downward forces.
D
Dermot
Guest
Banjo
I think you could be in trouble the word on the Morso underpinner is that it is not the best, try softwood wedges and only use Morso brand wedges.
Regds
Dermot
I think you could be in trouble the word on the Morso underpinner is that it is not the best, try softwood wedges and only use Morso brand wedges.
Regds
Dermot
fttom
MGF, Master Grumble Framer
Bill, if you will search for the thread, I posted a month or more ago information about a new clamp pad that I got from Pistorius for my VN-J. It is a "v"shaped clamp pad that replaces the round one that comes with the machine. Also, I have found that I have fewer problems joining my mouldings if, after I get everything situated, and the clamp in place, I wack the clamp handle with a rubber mallet once or twice. This makes sure that the clamp does not cut lose during the join. Since I got the new clamp pad, and have been using the mallet, my joins have been much better. I am one of the pickiest people in the world about good tight joins, and I have no problems with these now.
Also, are you using a saw or chopper to cut your mouldings? If you are using a saw, be sure that the moulding is not creeping into the saw blade as you cut. If you do not hold the moulding very tightly as you cut, with a saw, the rotation of the blade will tend to pull the moulding into the blade. You will, therefore get a slanted cut, with the top being wider than the bottom.
These two things should clear up a lot of your problems.
Also, are you using a saw or chopper to cut your mouldings? If you are using a saw, be sure that the moulding is not creeping into the saw blade as you cut. If you do not hold the moulding very tightly as you cut, with a saw, the rotation of the blade will tend to pull the moulding into the blade. You will, therefore get a slanted cut, with the top being wider than the bottom.
These two things should clear up a lot of your problems.