Dowel Pins

[George Bokros]

I am making a project and using dowel pins to keep panels aligned. I drilled the holes using my Jessem doweling jig. Purchased 3/8 dowel pins from two sources, they fit so tight I would have to tap them in. My understanding is if they fit that tight when they swell from the glue they could split my panel. Am I thinking correctly??

[jack duren]

Some you’ll have to tap in. When you glue on them, how about then?

[Cary Falk]

You can put them in the microwave for 30s to get some of the moisture out and shrink them somewhat. Past that, they might just be oversized and you might need a dowel plate or sand them down.

[Jim Becker]

For the purpose you are using them...you don't really need glue. Tight is good for alignment as long as your holes are drilled true, too.

[Jimmy Harris]

I've bought quite a few premade dowels over the years that were oversized a good bit from what they were listed. Depending on the thickness and moisture content of the wood you're drilling your dowel holes into, it may or may not be a problem.

But what I usually do in these cases is just shave a flat spot on the dowel. That way, it has room to expand, should it need to. So long as the wood it's going into is thick enough not to crack if the dowel expands, it'll deform the dowel somewhat as it expands into the space created by the shaved edge. That's my theory anyway. And so far, it's held up.

Sometimes is the dowel is really thick, I'll install it into a drill chuck and sand it down, run it through a doweling plate, or just shave off a bunch of corners with a spokeshave to get it back down to size. It should be a tightish fit. But you definitely don't want too tight. Don't worry too much about the expansion created by wood glue. Once the glue dries, it'll shrink back down to size. It's the expansion that happens after that that matters.

[jack duren]

Can you start it or have to hammer it all the way in? Do you have spiral or grooved dowels?

[James Jayko]

I would assume the pins you're using are steel, and you're using wooden dowels. Wooden dowels will compress substantially, I think you're probably good.

[Prashun Patel]

I've never had a dowel or domino split a panel by swelling from the moisture in the glue.

I wouldn't worry about it.

[Philip Glover]

George,

A simple way to reduce dowel diameter is squeeze it with pliers or in a vise. Squeeze evenly all the way around so that it does not go too oval. Check the fit, however, while doing this so that it is not made too small.

Phil

[Cameron Wood]

I also have never had a dowel split a panel from swelling.

[Mel Fulks]

I’ve got ,somewhere , a steel plate 1 inch thick that came from a junk yard , I drilled holes of different sizes , all slightly undersized .
So when the dowels are hammered thru they get skinnier and easily go in. I thin the yellow glue a bit to make sure they swell . It’s old stuff now
not used much, but still works. All the Old Timers I worked with had the homemade steel plates. I think there are still store- bought
Plates ,but the ones I’ve seen were too thin to work well.

[Richard Coers]

Another vote, wood dowels will not split a panel

[jack duren]

So you can put a 3/8 dowel in a 1/4 hole without splitting? Would that be considered a wedge of some kind?

[Jim Becker]

So you can put a 3/8 dowel in a 1/4 hole without splitting? Would that be considered a wedge of some kind?
Of course that would cause an issue. But I suspect that there is a presumption here that the holes and the dowels are matched for size, even though the OP indicates they are snug.

[Michael Burnside]

I’d probably check the bit isn’t old and needs to be replaced. If they’re a little snug I wouldn’t worry or if I did, I’d sand them a bit.

I’m with Jim on 3/8 dowel in 1/4 hole, yep that’s a problem LOL

[George Bokros]

UPDATE........

They dowel pins were so tight they would not go in by hand more than a quarter inch. The bit is not old, it has been used only few times. I chucked the pins in the drill press and using a file i slimmed them down to fit.

Thanks for all the replies.

[Steve Demuth]

I wonder at the logic behind the idea that a dowel would swell and split a panel. Assuming you don't cause the split when driving the dowel in because the dowel is way oversized, there isn't much expansion force to be reckoned with. To get a 1/4" pine dowel to expand its diameter one hundredth of an inch, you'd have to increase its moisture content overall by 20%. That's a lot of water to get out of a thin layer of glue. And that .01" would only apply at the point on the circumference of the dowel nearest the panel surface - everywhere else the force is reduced both by the smaller perpendicular span of the dowel. In addition that force is going into the damaged side of a hole where the wood fibers are more compressible than in fully intact wood. Just not much there, there.

[Bill Dufour]

You confused me until I realized you mean a wood dowel. To me a dowel pin is a precision ground metal rod which better be accurate diameter to 0.001" or better. Of course the holes are drilled then bored to size often 0.001-0.003 undersize.
Bill D

[Ole Anderson]

To me wooden dowels are called dowels, dowel pins are steel pins ground to a specific diameter. But then I do see a lot of wooden ones called dowel pins on a google search. Go figure.

[Kent A Bathurst]

I wonder at the logic behind the idea that a dowel would swell and split a panel. Assuming you don't cause the split when driving the dowel in because the dowel is way oversized, there isn't much expansion force to be reckoned with. To get a 1/4" pine dowel to expand its diameter one hundredth of an inch, you'd have to increase its moisture content overall by 20%. That's a lot of water to get out of a thin layer of glue. And that .01" would only apply at the point on the circumference of the dowel nearest the panel surface - everywhere else the force is reduced both by the smaller perpendicular span of the dowel. In addition that force is going into the damaged side of a hole where the wood fibers are more compressible than in fully intact wood. Just not much there, there.

There you go, Steve, usng science and logic to ruin a perfectly fine apocalyptic scenario. What's next - you gonna tell me I won't sail over the edge of the world?

[Tim Andrews]

I will second the method of dehumidifying the dowels in the microwave. I use dowels a lot with a Dowelmax jig, and this is part of my workflow. Since I live less than a mile from the ocean in the foggy Bay Area, I probably experience this problem more than most. I have gone up to 3 minutes in the microwave for stubborn ones. As I’m dry fitting a project I will sort them according to thickness and store them in air tight zip lock bags.

I have read that the drill bit that comes with the Dowelmax 3/8” kit is slightly oversized, although I don’t know this for sure and don’t know about Jessem. I replaced my bit when it became dull with a 3/8” one, and I do seem to experience tight dowels most of the time. I’m going to try a slightly larger bit that still fits in the guides.

[Rick Potter]

Thanks Mel, for the mention of the inch thick plate. I have a plate about 10" square and at least 3/4" thick in the shop that I picked up at a garage sale. I use it often to flatten metal pieces, but never thought of drilling holes in it for dowel sizing.

I'm gonna drill a few holes on one corner for sizing dowels, thanks to you.

[Michael Schuch]

I have been using dowels for joining wood for decades. I have never had a work piece split from a dowel swelling.

[jack duren]

Doweling isn’t as complicate$ as some of you make it out to be. It either fits or it doesn’t, it ain’t rocket science..

Microwave a dowel. I bought 10,000 dowels in the 80’s and I’ve used them on face frames, I’ve never had to microwave a dowel on any flavor or wood..

[Mike Henderson]

I find the commercial dowels to be large. I drive them through a Lie Nielsen dowel plate before using.

I only use dowels where I can't use a Domino.

Mike