PVC Dominoes

[waltwood]

Does Festool or any one else make a PVC Domino for joining products like Azek?

 

[peter halle]

Festool doesn't and I admit that I haven't done much searching for them, but another company that used to make dominoes has ceased production to the best of my knowledge.

In an effort to be helpful, and as one of several guys here who has used dominoes with exterior pac, what are you planning to use them for, are you using any sort of pvc glue, are all sides visible?

Peter

 

[waltwood]

I make many custom tapered columns, sills and other exterior millwork with PVC cellular material. I use trimhead screws now but I have to fill the holes and paint all of it. I use Azek glue. If I could use Dominoes I could omit the screws in some assemblies.

Walt

 

[peter halle]

I'll give you my experience, mine will differ from others.  In my usage the dominoes are for registration.  If I can get away with pocket screws I will use those to give the joints strength.  Of course in your situation you will only be able to do that on 2 joints of a column.  I use either standard or sipo dominoes.  The glue should be making a watertight joint and the wood is actually stronger than pvc would be.

Hopefully Brice will see this thread because he also uses dominoes and if I remember correctly sometimes makes his own.

Peter

 

[bkharman]

I know there was a thread about this in window sashes/frames. Mainly the silplate I believe.

Net/net, you could use dominos for alignment of the PVC parts and they wouldn't need to be sipo as they would be inclosed in the structure fully sealed so to speak.

 

[Brice Burrell]

I tend to use a lot of PVC trim and sheets.  I pull out the Domino about once a year for PVC.  As Peter mentioned I use PVC dominos that I've made myself.  The dominos I made are not rounded on the edges so they won't give a perfect registration in two planes.  Meaning you can register faces but not ends of work pieces.  You could make PVC dominos that fit perfect if you really wanted but I'm not convinced it's worth the trouble.  I say it's not worth it because you can just use the wood dominos without any hassle.  Really the bigger issue is that I don't think dominos offer any additional strength or reinforcement to the joint, assuming your joint is correctly glued with PVC glue.  The benefit you get is pretty much alignment only. 

In your application I believe dominos would be for alignment while you clamp?  If so just try using the wood dominos, remember you'll need to glue and go clamp crazy without using screws. 

 

[waltwood]

That is helpful. I don't use the Domino on its narrowest setting anyway so the side to side fit is not a problem. I do have a concern about using the wood with the PVC- different expansion rates and rot. I see jobs done where PVC was used and many of the joints have opened up. I don't think the glue prevents that from happening. I use the sipo for exterior but I am currently repairing a project that I did 9 years ago and I used Angelique for column bases and even that has some rot occuring. It was supposed to be a very rot resistant species.
Walt

 

[leakyroof]

That is helpful. I don't use the Domino on its narrowest setting anyway so the side to side fit is not a problem. I do have a concern about using the wood with the PVC- different expansion rates and rot. I see jobs done where PVC was used and many of the joints have opened up. I don't think the glue prevents that from happening. I use the sipo for exterior but I am currently repairing a project that I did 9 years ago and I used Angelique for column bases and even that has some rot occuring. It was supposed to be a very rot resistant species.
Walt

  Had to google that Angelique wood to satisfy my questions about it. Wow, you're right, it's not supposed to do that, wonder what went wrong.  Water getting trapped in the column and not enough air flow to dry it out?  [eek]

 

[Brice Burrell]

That is helpful. I don't use the Domino on its narrowest setting anyway so the side to side fit is not a problem. I do have a concern about using the wood with the PVC- different expansion rates and rot. I see jobs done where PVC was used and many of the joints have opened up. I don't think the glue prevents that from happening. I use the sipo for exterior but I am currently repairing a project that I did 9 years ago and I used Angelique for column bases and even that has some rot occuring. It was supposed to be a very rot resistant species.
Walt

My experience with joints opening is a bad glue joint.  When the glue is done right the joint is very unlikely to open, in fact I've had pieces crack from expansion/contraction but the glue joints held.  Also I've had to take apart a few things that have been glued and I ended up breaking the pvc itself more often than the glue joint letting go. 

My ideal joint is one that is pocket screwed and glued.  If the joint pulls tight you can remove the screws after the glue drys because the parts are fused together.  In your case where you can't pocket screw all the pieces of a column you'll want to really be sure you have it clamped well.  Another option, and I've never tried it, is a lock miter joint.     

 

[Brice Burrell]

Oh, I forgot to comment on the wood tenon in pvc with expansion/contraction.  Don't worry, again, if the joint glued correctly (don't bother trying to glue the tenons) it won't matter one bit.

 

[waltwood]

That is helpful. I don't use the Domino on its narrowest setting anyway so the side to side fit is not a problem. I do have a concern about using the wood with the PVC- different expansion rates and rot. I see jobs done where PVC was used and many of the joints have opened up. I don't think the glue prevents that from happening. I use the sipo for exterior but I am currently repairing a project that I did 9 years ago and I used Angelique for column bases and even that has some rot occuring. It was supposed to be a very rot resistant species.
Walt

  Had to google that Angelique wood to satisfy my questions about it. Wow, you're right, it's not supposed to do that, wonder what went wrong.  Water getting trapped in the column and not enough air flow to dry it out?   [eek]

I got the Angelique from the building of the Pilot Schooner Virginia in Norfolk, Va. It was the best modern shipbuilding wood afew years ago and that could have changed. It is horrible to work with- the dust, smell and it is rough on tools. I have done about a dozen projects with it and hope to never use it again. Where I used it and I saw the rot yesterday, water could could collect and stay there, but I did not think that mattered due to the rot resisitance of tyhhe species. I did provide weep/ air holes under the column bases in 2 directions where it contacts the deck.

I am glad it happened on my house instead of a customers. I can take my time repairing it and I won't feel like I am losing money or getting a bad reputation.
Walt

 

[JPF Woodworking]

I like to pre-assemble PVC window trim (exterior) on a flat surface and then install as one piece (two verticals and one horizontal). Pocket screws and PVC glue really does the trick. However, I did try to incorporate the use of the Domino was part of this assembly process and it worked quite well but since the Dominos are wood I have stepped away from that but sincerely wish PVC Dominos were available. I could (probably) mill my own but not sure it would be worth the extra effort. The point I am trying to make is that i can think of a number of applications where a PVC Domino would be great.

 

[waltwood]

I like to pre-assemble PVC window trim (exterior) on a flat surface and then install as one piece (two verticals and one horizontal). Pocket screws and PVC glue really does the trick. However, I did try to incorporate the use of the Domino was part of this assembly process and it worked quite well but since the Dominos are wood I have stepped away from that but sincerely wish PVC Dominos were available. I could (probably) mill my own but not sure it would be worth the extra effort. The point I am trying to make is that i can think of a number of applications where a PVC Domino would be great.

That is what I was trying to say is that I would have a use for them.
I could make them too but it does not mill like wood so I think they would be loose or too tight

 

[jamste]

You could probably try making them yourself. You could buy rectangular PVC extrusion and just use a round-over profile cutter on all four corners them cut them to length. Probably better to make more than less in one go to make it worth your while.

Best thing would to find a shop with a moulding machine and just have them feed the extrusion in and it can profile all four corners in one go.