# Pierced Chamfered Trefoils - how-to picture story.



## JCJCJC (May 15, 2012)

I often use pierced chamfered trefoils in my woodwork - very easy to do, and even though the origins are in classical ecclesiastical architecture, the geometry is absolutely made for the router. So, I thought I'd document one step-by-step example. This would be a lovely technique for a novice router pilot to try, it can be done with the cutters you'll get in a budget general-purpose set.

Step One - carefully set out an equilateral triangle where you want the trefoil. The length of each side should match your drill bit - in this case, 3/4" Forstner bit. Make the setting out markings lightly - so that the finished holes will overlap them, eliminating the need for sanding them off later. For me personally, 3/4" is the smallest hole I can get my finger in with some sandpaper for a final quick rub, keep that in mind if you're tempted to use smaller bits.








Step 2 - Using a bradawl, make small indentations at the corners of your triangle, just enough to engage a small drill bit.








Step 3 - drill through-holes with a small twist bit, this is 3mm, or 1/8", don't worry about break-out at the rear but go easy as it breaks through anyway. Raise the bit from the hole a few times to clear the swarf, it's supposed to help keep the hole straight and plumb.








Step 4 - chuck the 3/4" bit, use the small holes to guide its point, and drill only a little way into the top, or face, of the workpiece. The reason is you'll be doing most of the drilling from the back. You drill from both sides to get clean entry and exit holes, but inevitably there's a fuzzy bit where the two holes meet. Making the top hole shallow means the fuzzy bit will be removed in the chamfer - hope that makes sense.








Forstners make plenty of chippings, so use a vacuum to see what you're doing.








A drill press is almost an essential to keep the holes plumb. I find that the pilot holes area big help, and once the forstner bit is in to any depth it tends to keep itself aligned in the hole anyway.








Once you've drilled a little way from the front and the rest of the way from the rear, it's time to use the bearing-guided 45-degree chamfer bit, don't have it extended by more than approx 3/16ths, test on a piece of scrap if you're not confident. Note that the fuzzy bits disappear once the chamfer is routed..

















Isn't that nice? Well, I think so anyway. All that's left on this project is to cut it out, buzz the same chamfer bit around the edges, a quick rub of chopping board oil, and we have a nice little ash chopping board ready to go:








Here's another one with trefoils at each end, in beech, just to show another use of the design element:








On the beech one, I've rounded the outer edge rather than chamfer it - just my taste at that moment.


I hope somebody likes this idea and tries it.

JC


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## carlp. (Nov 3, 2012)

*trefoils*

hi JCJCJC the chopping board is very nice i hope you are making some money out of them, should sell well on the craft market. regards carl


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## JCJCJC (May 15, 2012)

carl.p said:


> hi JCJCJC the chopping board is very nice i hope you are making some money out of them, should sell well on the craft market. regards carl


Thanks Carl. I'm not making them to sell myself - just trying to develop a few ideas for a friend who wants to run a Christmas craft stand at a market in England. I'm trying to discover what is quick and easy to make, yet looks attractive and substantial and significantly different from mass-produced boards. I've made about ten different designs so far. I find that trefoils and chamfers add visual interest, the detail holds the eye. For food products, I prefer relatively plain grain - if a piece has flaws giving it character, I make trays, candle stands etc to try to maximise the rugged look of the wood. I don't like waste, I try to find some use for nearly every piece of wood I mill.


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## Gaffboat (Mar 11, 2012)

John, very nice, easy-to-do design that adds a lot of visual appeal to what is essentially a simple piece. Thanks for the great idea. We'll be visiting Ireland in May and hope to find some ideas I can steal ... I mean borrow ... oh, let's just call it Research. :laugh:


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## JCJCJC (May 15, 2012)

Gaffboat said:


> John, very nice, easy-to-do design that adds a lot of visual appeal to what is essentially a simple piece. Thanks for the great idea. We'll be visiting Ireland in May and hope to find some ideas I can steal ... I mean borrow ... oh, let's just call it Research. :laugh:


Hiya Oliver - have you made hard-and-fast travel plans, or are you open to suggestions? Would you know how to race a 34-foot yacht?

JC


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## Gaffboat (Mar 11, 2012)

We have hard and fast plans, we are doing an Ireland Whiskey Tour visiting the Jameson Distillery in Dublin, Locke's Old Kilbeggan Distillery, Tullamore Dew Heritage Center, Cooley Distillery, Bushmills in Northern Ireland and a few other places over a 10 day period. Yes, I DO like Irish Whiskey. :sarcastic: 

I have no clue about racing a 34 foot yacht but that does sound like fun. Are you racing your own boat?


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## JCJCJC (May 15, 2012)

Gaffboat said:


> We have hard and fast plans, we are doing an Ireland Whiskey Tour visiting the Jameson Distillery in Dublin, Locke's Old Kilbeggan Distillery, Tullamore Dew Heritage Center, Cooley Distillery, Bushmills in Northern Ireland and a few other places over a 10 day period. Yes, I DO like Irish Whiskey. :sarcastic:
> 
> I have no clue about racing a 34 foot yacht but that does sound like fun. Are you racing your own boat?


Not a bad tour. I thought from your username that you might be a boat nut. I crew a 34-foot yacht, we race every wednesday in May, and we can usually take a few extra crewmembers, we're allowed up to eleven on board under the rules. To be honest, yacht racing isn't always very pleasant for initiates, it's speed before comfort, always.

This is us.


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## jw2170 (Jan 24, 2008)

Nice yacht, John.

I used to crew (2 up) on a 37 ft and 28 ft yacht.......Spinnaker work as well.....

I still look at the weather and say to Maree, " a nice day for sailing, Dear" up to about Force 5.....LOL


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## Gaffboat (Mar 11, 2012)

You are correct John, my username is sailing related. It goes back to a little gaff-rigged sloop I built about 10 years ago. Rather than fast and hard, my sailing was slow and easy because I'm basically a lazy guy. The boat has since been passed on to a younger sailor.


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## JCJCJC (May 15, 2012)

James - I'd be worried about safety with 2 on a 37-foot, in any kind of wind beyond very gentle breezes.

Gaffboat - well done on building a boat, it must give an amazing sense of achievement. Racing is very different from cruising sailing, things break, usually under big loads in big winds and seas. I've seen winches snap all their pawls, boom kicker tearing free, spinnaker downhaul tearing out of the deck, tiller snapping off etc, and I've seen masts break on other boats.

Still - it isn't all high adrenaline stuff, I took this pic at sunset on a four-day trip to France on a 50-footer with auto-everything:


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## JCJCJC (May 15, 2012)

James - I'd be worried about safety with 2 on a 37-foot, in any kind of wind beyond very gentle breezes.

Gaffboat - well done on building a boat, it must give an amazing sense of achievement. Racing is very different from cruising sailing, things break, usually under big loads in big winds and seas. I've seen winches snap all their pawls, boom kicker tearing free, spinnaker downhaul tearing out of the deck, tiller snapping off etc, and I've seen masts break on other boats.


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## jw2170 (Jan 24, 2008)

JCJCJC said:


> James - I'd be worried about safety with 2 on a 37-foot, in any kind of wind beyond very gentle breezes.
> 
> Gaffboat - well done on building a boat, it must give an amazing sense of achievement. Racing is very different from cruising sailing, things break, usually under big loads in big winds and seas. I've seen winches snap all their pawls, boom kicker tearing free, spinnaker downhaul tearing out of the deck, tiller snapping off etc, and I've seen masts break on other boats.


Thanks for the concern, John.

This was racing in enclosed waters. The highest we saw was 30+ knots of wind gust.

The yacht was a 37 ft ocean racing boat that had taken part in a number of ocean races including the Sydney - Hobart. ( that was with a full crew).

The owner and mentor was a Finn with 50+years experience. It all gets down to knowledge and teamwork.

We never took any risks and never had anything break...

The 28footer (an old 60's cruiser - Compass 28) won every trophy in the club (except the ladies skipper race, as I would not wear a skirt) and the club championship on handicap at least 3 times, over 10 years, while I crewed.

We took her out one day in 25-30 knots with 2 reefs in the main and a couple of furls in the headsail. - great sailing....

I suppose you could say it was like a wood worker who never used guards and still had 10 fingers.......


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## JCJCJC (May 15, 2012)

You're a tougher man than I am James! When one of you was winching, and the other tailing, who was helming - let alone trimming the main? This is us in action again. The picture was taken by the Race Committee, full sure we were going to collide with their boat - hard. Our skipper has nerves of steel, he called the tack at the absolute last second, knowing the crew knew how to handle the boat smartly - she'd have been doing about ten knots at that stage.








Anyway, getting back to making trefoils, the interest shown in this thread made me do something that has been in my mind for a while - trefoils through a template, to save time. Well, it can be done - I made a plywood template, with side bits, I suppose I can call them dagger boards seeing as there's so much sailing guff going on:








The side bits keep the routs a consistent distance from the corners, using several clamps:








And with a bit more dickying-up with the chamfering bit another almost useless piece of ash with a big dirty mark lives to fight/light another day ;-)








No finish on that yet, I'll rub on some Danish Oil, probably.

JC


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## jw2170 (Jan 24, 2008)

Glad you got us back on topic, John.

LOL

We could talk sailing for hours....VBG.


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## ChadPMIK (Jun 28, 2013)

Thanks for sharing


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## JCJCJC (May 15, 2012)

*Another little project with trefoils...*

This footstool is a design I use again and again, people fall in love with the stools and run off with them. This time I wanted to try out my new Bosch Router Inlay Kit - it certainly works, I love it. I used it with the Milescraft kit to inlay the flower on this top. The stool is made of elm, the inlay is holly.


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## vzbingo (Mar 1, 2012)

Very nice, John. I hadn't considered the trefoil design but it is a good looking one. Thanks for the pictures & the how-to.


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## jw2170 (Jan 24, 2008)

Very nice, John. Should be a hit at the markets.


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## old55 (Aug 11, 2013)

That looks really nice John.


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## JCJCJC (May 15, 2012)

*Thanks*

Thanks, everyone, for your kind remarks. JC


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