The Framers Forum

While on the topic of wedges.
Is there a convincing argument for using softwood wedges in soft wood?

I use hardwood wedges exclusively, they seem to be fine when used with soft wood

Likewise, we use hardwood wedges all the time, and we do a fair amount of bare faced softwood frames. For us they work fine.

How do you define softwood - the majority of mouldings are hardwood.

I'm confused.

You'll find a definition (hardwood/softwood) here: -
http://science.howstuffworks.com/question598.htm

balsa wood is one of the lightest, least dense woods there is, and it's considered a hardwood

"Hard wood" is not the same as hardwood. Can someone clear this up? In terms of wedges, are we talking about hard wood or hardwood?

I occasionaly get customers asking what woods used in the frame - they look at the chevrons and occasionaly remark that they would like a hardwood frame - this stuff looks very soft. I always ask them how they define hardwood - pointing out that balsawood is in fact a hardwood - in simple terms from a tree that loses its leaves.

Try using hardwood wedges on a realy hard and knotty bit of english oak and you will find that the definition is not all its cracked up to be as the wedge will often split if enough force is applied. (good tip with very hard wood is to use a piece of suitably shaped moulding on top of the moulding being joined - this tends to put more force on the hammer and will often drive the wedge in fully - without the added pressure the wedge will often just not go in deep enough and the joint will open up).

I only ever use hardwood wedges on the simple basis that most of the moulding I use is Hardwood - even when its very soft.

When joining "soft" hardwood, dont make the mistake that many framers make of putting in too many wedges. It doesnt improve the joint. In reality the wedge is realy helping the glue do its job and on large profile mouldings the best thing you can do to ensure a good joint is to allow the glue to set before joining the next side.

I broke up a frame the other day that must have had at least 1 wedge every 2mm - it wasnt glued and almost fell to bits on its own - the wedges had destroyed any real dynamic strength in the wood.

More So wrote: are we talking about hard wood or hardwood?

I think when we are talking about wedges we are talking hard wood / soft wood. The only difference I can see in the wedges is that the soft wood wedges are only sharpened on one edge, the hard wood are sharpened on both. this is presumably to allow them to penetrate easier.

I actually use soft wood wedges for everything, only because several thousand came with my underpinner, and have had no problems. Havent tried seasoned oak yet though.

Hard wood wedges in my experience will not stack very well…..I found you could only use one on each corner and the right glue for the wood use only one wedge and glue on hard wood.…..ie a good quality glue

In reality if you use the right glue all the wedge does is hold the moulding together till the glue sets……..ask a good carpenter about glues ……….

For the most part I never used anything but soft wood wedges….

I agree.

If it's a big moulding I use the longest wedges, as I have had little success with stacking any of them, they tend to slide down the side of the first wedge. I only put a small bead of good quality glue down the middle of one side of the joint, then it doesn't get all over the face of the moulding but gives a good joint. To much glue can actually weaken a joint

I was lucky that I inherited a very good pneumatic underpinner when I took on my framing business - I have since replaced it with a new machine that has 3 sizes of wedges so that i dont have to stack too often. Really hard wood is almost impossible to pin - Pins split - follow the grain and come out of the frame or just wont go fully into the wood - you can make up an oak frame and get a different result on all four corners. I can only say that if you run a profesional workshop you need profesional kit - if your using a foot operated underpinner then you wont get good joints on realy hard timber.