Blind M&T joint sucked in - HELP

[zemlin]

I am building a bed for my daughter - this is my first real furniture project and I'm learning a lot with every step I take. Most things I'm doing a dry-run on scrap lumber before I try it on the real thing, but I have encountered a problem I did not foresee.

http://www.zemlin.atfreeweb.com/bed_end1.jpg

To put this end of the bed together I used blind Mortise and Tennon joints.

http://www.zemlin.atfreeweb.com/bed_end1x.jpg

The remaining wood over the blind end of the mortise is pretty thin - less than 1/8". I used Titebond II glue to stick it all together. It all looked real good until I noticed that the thin section at the end of the mortise has sucked in about 1/64" on all the joints.

http://www.zemlin.atfreeweb.com/bed_end2.jpg

I assume this is a matter of using the wrong glue. What kind of glue should I have used for these joints?

I'm not sure how I'm going to recover from this mistake. I might sand the crap out of the area and try to feather the edges of the dips and hope it doesn't look too bad. I might cover the dips with some bogus moulding - although I like the simple design - I don't have any ideas that I think would look good.

Is there anything I might try to minimize or eliminate the dips on these joints? Would a heat gun be able to warm things up enough that the glue might let go a little - without weakening the rest of the joint?

Thanks.

[MadMark]

Ummm. There's probably not a lot you can do at this point without making things worse. If you pull on the joint you'll pull the sucked in area right thru. The strength of the sides of the sucked in area is less than the bond between the end of the tenon and the bottom of the mortise.

If you're going to paint some wood filler will level things out.

If you're going to stain, then sanding is your only real option.

You really shouldn't make your blind M&T that thin for the reason you've found.

For this type of blind joint a biscuit cutter may do as good a job without the cut thru issue.

M

[Dave in Cairns]

It's not the glue that is the problem here , so much as the mortise being too deep. As a general rule , the mortise should not exceed 2/3 rds of the thickness of the timber. Have you considered mortising from the outside and inserting dummy through tenon ends ? I'd be very wary of using biscuits and butt joints on any bed , let alone one that I'd want to keep. Always ask yourself , "will this stay together without glue?"
[link:www.australianwoodart.com|http://www.australianwoodart.com/galleries/g03/desk3.jpg]

[zemlin]

The plans I used as a guide for my design had faux tennons. I just thought it looked better without that detail.

I went ahead and sanded the areas feathering the dip out. I glued up the other end frame - everything was cut already so I couldn't use shallower mortises. I just have to sand that one too. I think it will look OK. Once finished I suspect the flaw will be visible to anyone who wants to find it, but it will be pretty slight.

Thanks for the input.

[Glen]

Dave has steered you right. You're proportions are off. I think I would attempt to get it apart and add a couple dowells as stops.
and use Gorilla glue because of it's expanding properties.

Glen

[Carl]

I agree with those who have posted prior.........it appears your mortises are to deep. But......depending on the type of furniture why not take the tenon all the way thru especially if you are staining and want an older style look. Shaker and mission style use alot of pegged tenons and they have great strength. If you still want to keep it as shown then just reduce the depth of the mortise and you could use some screws with plugs if you thought it was weak.

Have fun..........remember you are the only one who will know where all the mistakes are.........