Underpinner problems

[elly-d]

Hi,

I am having trouble with my mitre joining. I am pretty sure that my morso is set up well and that the blades are sharp (also sharpened by a trusted company), but when I join the pieces on my cassese cs79 the joint opens. The main problem is opening on the back edge ( not the face) of the moulding, Though recently the face isn't joining as well as it should, tight on the inner edge becoming more gappy towards the back.
Does this description ring any bells with anyone? What am I doing wrong?

Cheers.

Ellis.

[Roboframer]

Can the fences on that underpinner be adjusted? If so get a large tri square and adjust them to it - if the problem persists it must be your blade angle, and the best way to test that is to make a small frame with a large (say 1 x 9cm) flat batten.

[Not your average framer]

Is there another framer near you, (but not so near to be a competitor), who will help. Maybe a another forum member, if so this is the idea.

You make two small frames using wide flat timber sections. You cut one on your morso and join it on his underpinner and cut the other on his morso and join it on your underpinner. Whichever frame still having a problem will tell you which item of your equipment needs sorting.

It may surprise you that local framers are often not only on good terms with one another, but often help each when the need arises.

[Jared Davis CPF, GCF]

Yep - I got three possibly things that could help you...

1. Check the fences on your Morso are dead straight with the measuring arm, with a 1.0mtre long metal, straight edge ruler.
2. Never insert a wedge within 8mm of the back edge of a mouding... ever..!
3. Make sure the top clamp (bung) is pre-set to be only about 30mm away from the top face of the moulding before joining. ie: Lower it, if it is too high!

Cheers,

Jared

[prospero]

What type of wood? Is it worse with harder woods?

Sounds like a classic case of "not enough pressure on the top on the join" to me.

[philipsheldon]

Good Morning Ellis,

I have just read your recent posting on the Forum. Ashworth & Thompson are in Nottingham, not that far away from you. We have a fully experienced technician, Kevin Shelton, with over 40 years trade experience. If we can be of help, please call me, Phil Sheldon on ( 0115 ) 964 7507.

KInd regards,

Phil.

[iantheframer]

I think I agree with Prospero, if it is with harder woods, have you tried hard wood wedges. You will also need to change the bung to a hardwood version as the one for softwoods can compress too much, resulting in lack of pressure

[prospero]

Not sure how the pressure setting on the CS79 works exactly, but my trusty old Euro8001 is fairly tolerant re. pressure on softer woods, but on oak and ash the pressure needs to be very firm. Otherwise you get exactly the issue you describe. The wedge will tend to lift and seperate the underside of the join before going in.

[elly-d]

wow, thanks guys.

I will definately try a few things as soon as. I hate the cassese but Its all that I could afford so far. I do use hardwood wedges on anything over than the softest mouldings, and I use the L shaped add on pressure pad by Lion. I have no idea if you can adjust the pressure on this machine, its pretty basic and I haven't noticed any controls.

I think I have been wedging a little too close to the back of the moulding and I will slap my wrists for that, I think I will also have a good look at the old morso set up too. Its a pain when you are busy to have to mess around with crappy equipment and... well I suppose I shouldn't blame my tools eh?

Thanks.

[WelshFramer]

The pressure adjustment is your foot - for low pressure press gently.

Cassese recommend speeding up when the wedge starts to enter the wood. The faster the better. Not sure why but it does seem to help.

[vfmarky]

Just a thought...but is everything clear of old dried glue? I use old mat cutter blades to make sure the base plate and angle arm on my Inglet 1800 is super cleaned up (scraped) - any debris in the 'zone' can muck up a good join.
BTW I had a (new) Italian V nailer that had a WARPED base plate which gave endless open results, much blue air and wasted mouldings. So while you have the straight edge out on the Morso check the nailer platen!
And another thing...are you an L joiner or a chaser? By that I mean do you make up two L sections and join them or do you keep chase joining the rectangle?
I used to join Ls but now I chase the rectangle and I get perfect results 99% of the time. Love that Inglet.
Another issue is whether to put the inside V nail in first or the outside. I go for the inside first, again with good results.
Oh, the joys of framing...You have to love it don't you?
Regards, Markie

[elly-d]

Hi,

after using for a few more days and adjusting bits and bobs I am reporting back. I have been inserting the back wedge a safer distance from the back of the moulding but 'buldging' still occurs on most mouldings hard and soft (lots of filler being used at the moment). I insert the front wedge first, then work round anti clockwise not L joining? Also the wedges just don't seem to be pulling tight the joins open slightly without any force while being manouvered. I always use the deepest wedge the moulding can take, how do you guys use wedges? Configurations? Depths? amounts?

Ta

[Roboframer]

I found a utube link!

[youtube]7snjq9KWStM[/youtube]

Now I know what a cassesse cs79 looks like!

[iantheframer]

so if a moulding were 12mm deep and 18mmm wide, what size wedges would you use and how many?

[iantheframer]

Sorry that is a bit small as an example lets say 25 mm deep and 30 mm wide oak section

Or thoughts on both

[vfmarky]

Wedges? Que?
Oh, you mean V-nails, yes?

[iantheframer]

sí

[vfmarky]

OK, I'll be the first one to blink.
On a 25mm deep moulding I'd use one 15mm v-nail placed about 8mm from the front and about the same in from the outside. Plus LOTS of glue 'cos it's the glue that holds it all together, right?
Double stacking (say, two 10mm v-nails) isn't really necessary below 30mm deep, I would have thought.
"What does the team think?"

[prospero]

Is this a general question or just directed at Ellis?

Anyhow, Two 10mm hardwood wedges front and back (not too near the back). If the frame was bigger than about 20x16ish I might cross nail it as well near the top. Bigger than 24x36ish and I would add L-plates on the corners. If you give the L-plates a smart tap in the middle on the underside with a roundhead hammer, it just gives them a bit of bias to pull the face of the joint tight as the screws are tightened.

[MITREMAN]

"My go, My go"

The moulding being say 25mm high and a width of 30mm across the top in oak (American, very hard or even Ash) Flat section.
With 25mm across the bottom allowing for a minimum rebate of 5mm

I would try and get the largest wedge in as possible on a test corner before attempting to join the original.

1 wedge in from the back 8mm-10mm seems ok to me.
1 wedge in the front coming between 8mm-10mm (including 5mm of rebate, estimated size)
10 mm for both not stacked, Lots of glue

12mm- 15mm or stacked wedges on my under pinner would struggler to go into oak, even with a hard wood bung and pressure increased and hard wood wedges.

Router and a plug would be an option, or a nail in the top if needed.

MITREMAN