# wood dowel or not



## papawd (Jan 5, 2011)

I have been building some garden type benches for gazeebo area and always changing and wanting to try new ideas am wondering if wood dowels mayybe 1/4" would hold down seat slats or should I stick to screws .... I am building these out of cypress and have fluted Oak dowels or just a plain oak dowel rod .. it would give anice look but I am afraid over time it may bow up and the slats are planed down to 3/4" , I may just drill a small 1/4" hole in slat and then screw the slat finish with just a pretend dowel glued in any comments welcomed


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## OPG3 (Jan 9, 2011)

Warren, there are a couple of considerations for dowels and their strengths and weaknesses as follows:
Dowels can be subject to shear stresses - which is a force perpendicular to the overall length of the dowel in question. Think of toughness versus a pair of scissors.
Dowels can also be subjected to pullout stresses - which, as the name implies is a force attempting to pullout the dowel from the embeddment in a direction along the dowel's length axis. 

Back to your question, now. In your project the dowels are exposed to both of the forces - but I would venture to guess (not knowing all of your conditions) that pullout is where you will have a problem. 

If the wood gets wet, a couple of things happen:
Eventually with wet wood, you will get wet glue. Many glue joints fail due to erosion over time of exposure to varying conditions. Note: there are some glues much safer in this scenario than others. Obviously waterproof glues perform the best, here.
Also as wood soaks and dries, it expands and contracts - potentially affecting this joint.

Personally, I have found that pocket hole joints with stainless steel screws and holes that are drilled vertically upward have worked well for me. Horizontally drilled holes sometimes will work okay, but vertically downward holes are the worst - due to the holes becoming a catch-all for water and debris.

Certainly, you may see some items outdoors that incorporate dowels that have performed very well - it isn't that it cannot work, it's just that IMHO there are safer ways to construct that same joint. By the way, I am a huge fan of wooden dowels and probably use over 100 linear feet of them per week in my shop.

Good luck!


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## Mike (Nov 22, 2004)

Warren, I think the best way to go about this is to drill and counter sink holes, glue and screw the slats down and then plug the holes with home built plugs. This way you get the mechanical strength of glue and screws and the plugs protect them from the weather and have a nice look. This is the method I used on this porch swing and the end result was well worth the trouble of drilling and plugging 120 holes.


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## Gene Howe (Jul 10, 2007)

The dowel plug over the screw is the way I'd go. Although, pocket screws from the underside would leave a better topside appearance, IMO.
When we laid or redwood deck boards, we used the Trex hidden fastener system. But, there were places where they wouldn't work, so we counter bored and screwed the the boards down. To cover the holes, I cut plugs from redwood and epoxied them in place. I know, Titebond lll is supposed to be water proof, but epoxy leaves no doubt.
If you had 1.5" thick bench slats, I'd recommend the Trex system. Pretty slick.


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## bobj3 (Jan 17, 2006)

Hi

I would suggest forget the dowel way and use stainless steel screws/stainless steel carr.bolts they will stand up for many the years in the weather.. 

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papawd said:


> I have been building some garden type benches for gazeebo area and always changing and wanting to try new ideas am wondering if wood dowels mayybe 1/4" would hold down seat slats or should I stick to screws .... I am building these out of cypress and have fluted Oak dowels or just a plain oak dowel rod .. it would give anice look but I am afraid over time it may bow up and the slats are planed down to 3/4" , I may just drill a small 1/4" hole in slat and then screw the slat finish with just a pretend dowel glued in any comments welcomed


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## Phil P (Jul 25, 2010)

One other consideration about dowels is the material they're made from. Most store-bought dowels seem to be made from beech. Unfortunately beech isn't a durable timber and shouldn't be used for outdoor projects. Thet would leave you having to source a suitable timber and a completely waterproof glue, such as urea formaldehyde/resorcinol formaldehyde glue (plastic resin glue)

Regards

Phil


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## pal (Feb 13, 2008)

Hi
I made a couple of adirondack chairs and a couple of porch chairs, went the way of Mike with glue, stainless screws and a plug made of the same timber, aligned the grain of the plug with the grain of the slats you can hardly pick out the plugs.


Regards
Harold


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## MACswag (Feb 28, 2012)

smashing swing bench, MAC


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## Dimitri M (Oct 4, 2011)

Mike I agree with your opinion re. screws and wood plugs on top.

Warren, have you already built it ? How does your cypress behave in humidity / sunshine? what finish? You say you live in the US, it can be as hot as New Mexico, humid as Louisiana, cold as Alaska and all shades of gray in-between. Be more specific in terms of climate?

IMHO, cypress - here in the Mediterranean - is not good for outdoor use, as it has the ntendency to split and warp - if you see my threads you will understand how I deal with it. Dowels themselves NEVER exert compression between two joined pieces of wood, and eventually they will give way in shearing forces, so screws under and a plug on top is extra work of course, but with better results. The show of screwheads, no matter how shiny, give a poorer appearance than plugs, and if the screws showing get dented they will catch on clothes or ladies' stockings and degrade your work. The glue for plugs needs to be waterproof, whatever this means for US glues, I notice that ads in US wood magazines have only the brand name and not what the product is made of. Waterproof glue stains the wood - will you paint it or stain it ? Extra work again.

Let us know what you achieved or what your plans are.

Best wishes


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## Cherryville Chuck (Sep 28, 2010)

One more nix for dowels. I've tried them and they eventually let go. One other consideration is that dowels form a solid, unmoving joint. Anything outside, even if it is under cover, is subjected to dimensional changes because of the weather and racking forces when being used. Mechanical fasteners allow some movement without weakening the joint.


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## bobj3 (Jan 17, 2006)

I will 2nd Charles post I hate dowel pins..

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Cherryville Chuck said:


> One more nix for dowels. I've tried them and they eventually let go. One other consideration is that dowels form a solid, unmoving joint. Anything outside, even if it is under cover, is subjected to dimensional changes because of the weather and racking forces when being used. Mechanical fasteners allow some movement without weakening the joint.


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