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Thread: dowel pins too tight (follow up on Jessem dowel jig)

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  1. #1
    Join Date
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    Jessum Pins with Jessum Jig

    Quote Originally Posted by Paulh Tremblay View Post
    I could have used a mallet to hammer the joint together, but I don't believe you should fit dowel joints together that way. The videos for Jessem and Dowelmax show the joints going together easily with the push of a hand.
    Has anyone experience with the dowel pins sold by Jessum? I would expect their pins to match quite well with their own jig. Seems better to me than the various re-sizing schemes discussed in this thread. I haven't yet ordered them but plan to give them a try.

    The company describes their pins:

    Our pins absorb some of the glue moisture and expand to take up the space left by the shrinking glue, creating an excellent mechanical and chemical bond.

    Our Expansible Dowel Pins are milled round and slightly oversize, then grooves are impressed into them creating an accurate, strong, joinery element.
    Attached Images Attached Images

  2. #2
    Quote Originally Posted by David Winer View Post
    Has anyone experience with the dowel pins sold by Jessum? I would expect their pins to match quite well with their own jig. Seems better to me than the various re-sizing schemes discussed in this thread. I haven't yet ordered them but plan to give them a try.

    The company describes their pins:

    Our pins absorb some of the glue moisture and expand to take up the space left by the shrinking glue, creating an excellent mechanical and chemical bond.

    Our Expansible Dowel Pins are milled round and slightly oversize, then grooves are impressed into them creating an accurate, strong, joinery element.
    Jessem, DowelMax and Lee Valley all get their dowels from the same supplier.
    Those dowels work great with the 9.7mm guides and bit but are just a little oversize for a 3/8" bit.

  3. #3
    Could the 3/8 inch Jessem guides be drilled out to 9.7 mm?

  4. #4
    Quote Originally Posted by Jack Clay View Post
    Could the 3/8 inch Jessem guides be drilled out to 9.7 mm?
    No. The bushings are hardened steel.

  5. #5
    Join Date
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    Quote Originally Posted by Paulh Tremblay View Post
    No. The bushings are hardened steel.
    I guess I am repeating myself multiple times. Just slightly enlarge your bushings with a sand paper wrapped around a 1/4" dowel rod and rob the bushing all around. You just need to take about 0.001" or 0.002" from each side. Then use 9.6mm or the V-drill bit which are between 3/8" and 9.7mm. You won't have all these problems anymore....
    sigh...

    I have both versions of Jessem jigs and have drilled thousands of dowels with them.

  6. #6
    I contacted Jessem, and the rep informed me I should just put the dowel pins in the microwave. I put 20 pins in the microwave for 2 minutes, and it made a complete difference. My joint came together during a dry fit with just hand pressure. For my first glue up, I needed tremendous force with clamps, and an edge developed a slight crack. For my next glue up I coated the dowels with a very thin coat, and the joint came together with normal clamping pressure.

    I am a bit concerned I cooked the dowels too long. Some came out of the microwave with brown specks. I asked Jessem, and was told that you can in fact heat dowels too much, but didn't get any more direction than that.

  7. #7
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    I will make the argument that no matter how you pick bushings and drills, variability in dowels, just like biscuits, really suggest the use of a dowel plate to resize them just before insertion in your joint. Remember the toy we had as little kids where we used to pound the peg through the hole? Same idea. Everything really important we learned in kindergarten. Just Google dowel plate. And you don't need to buy the $55 Lie-Neilson one either, you are better off making your own. Step into metal working, it is fun too.
    Last edited by Ole Anderson; 09-10-2014 at 9:17 AM.
    NOW you tell me...

  8. #8
    I use this dowel plate but just the inserts which fit in a dog hole:

    http://www.leevalley.com/en/wood/pag...55&cat=1,42524

  9. #9
    Got new dowels direct from Jessem. They were the same as I ordered from a third party, Just Joinery. They recommend:

    "If you find your joints too tight, our Expansible Dowel Pins can shrink about .002” by putting them in a warm oven at 200°F or 93°C for 20 minutes on a clean cookie sheet. Warm the oven then shut it off before putting the pins in."

    I did exactly this. The dowel pins fit a bit tight, and during dry fit I needed a pair of pliers to remove them. But glue up presented no problems. I made sure to use to rub my finger over the dowel to remove the excess glue and leave just a very thin layer.

  10. #10
    Join Date
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    I have the new style Jessem Jig, and I noticed I had issues with the 1/4" Dowels being too tight. I got the dowels from LV, and they are .005 oversized (They say this on package). My Jessem Drill bit they provided was .002 less than 1/4". This makes it tight enough where I have to get a mallet to pound in the dowels, and I have to use some major clamping pressure to close the joint.

    First time i used it I split the wood cause the joints were so tight.

    Im not sure either what I should do
    -------------------------------------
    Adrian Anguiano

    "For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future". Jeremiah 29:11

  11. #11
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    Austin Texas
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    Same answer for all dowel sizes - either dry the pins out in an oven/microwave, or drive the pins through a sizing plate prior to use. Sizing plate seems easier to me, but either way. I don't see how any brand of dowels ordered from any source could be guaranteed to be of any exact diameter 100% of the time.

    David
    David

  12. #12
    Join Date
    Jan 2011
    Location
    Fort Worth, TX
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    Yea, but the dowels are exactly what they said they are supposed to be. Which makes me wonder if something else is going on
    -------------------------------------
    Adrian Anguiano

    "For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future". Jeremiah 29:11

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