Mast Hoops

[RT MAN]

Going to use this to make my mast hoops. 1/4" x 3/4" white oak.

http://s46.photobucket.com/albums/f118/Alerion111/th_Moldwithstrap2.jpg

[Vinny&Shawn]

Look at WoodenBoat Magazine #206 page 101, article and book by Pert Lowell company. Might shed some light on a simple method. I used a jig that I could steam the ash strips and mold them to the inside rather than an outside mold. I could clamp the hoops all around the perimeter. They came out very nice, an 8' strip of wood yields a 10" diam. hoop.
I'll post some pictures!!

[Vinny&Shawn]

These hoops were my first attempt, not so round but strong and sound. The other 8 resulted in very acceptable examples,put 4 on the mast and 3 on board for spares. It was my own rendition using Lowell hoops for a guide to measurements and finish. These types unbolt and corkscrew onto the mast.
http://i419.photobucket.com/albums/pp278/vgeorge1/Boyscamping005.jpg?t=1237505984
http://i419.photobucket.com/albums/pp278/vgeorge1/Boyscamping004.jpg?t=1237506031

Next time I make some I will try the Lowell method, and an outside bending mold.

[RT MAN]

Going to use this to make my mast hoops. 1/4" x 3/4" white oak.
http://i46.photobucket.com/albums/f118/Alerion111/IMG_3353.jpg?t=1237473259

My 5.5" circle is almost perfectly round with exception of a few misguided nick from the jig saw. The oak strip fit tightly into the groove so it should hold the strip while I bend it around the template. With any luck it will soften enough that I can get a good even bend. I did read the Pert and Lowell article in WB although I think I will have to gop back and read it again because I don't recall it.

I will post more pics as soon as I start steaming, Next I'll make a steam box.

Rufus

[Vinny&Shawn]

Sounds good I'd like to see the progress,plan on making some more myself!

[RT MAN]

Well my first attempt at steaming the oak and making nice smooth bends around the 5.5" mold did turn out like the first time.

So I will have to try it again. This time I might try some different wood. It definately was hot enough to burn my hand through a good pair of American Ropers.

As I bent the the strips around I could feel the crack I don't know if it was a weak point or just a dry spot in the wood. The soak in water for at least 10 days and there was lots of water squeezing out as I bent it around the mold. I also felt if I pulled quite hard on the strip it eased the bending and help make a smoother transition from straight to curved.

Eight strips I cut and steamed only one would be considered passable but for the fact that it was to short by about 4 inches. ( it did quite make it a full 2.5 times around when I calculated out the length I forgot to take into account for the thickness if the strips themselves).

I used 1/4 inch thick strip for a 5.5 in mold I'm not really sure if their to thick for a 5.5" mold.

Some input would be nice from some one with experience.

Rufus


http://s46.photobucket.com/albums/f118/Alerion111/

[Wooden Boat Fittings]

.
I'm afraid I don't know anything about the properties of White Oak, but I have a gut-feeling you'd be better off using 1/8" strips instead of 1/4" (even if it means making the hoops in two stages to build up to the thickness you want.)

Mike

[Sailor]

A 1/4 by 1/4 inch length of WO will allow you to tie it in a knot if you steam it properly. Then it will set in that position. The 1/4 by 3/4 should bend in a curve tight enough for that without too much difficulty if you steam it properly.
What wood would you use in Canberra for this purpose? I guess it goes to show that what we take for granted (WO) others may never have heard of.

[RT MAN]

Wooden Boat Fittings I'm going to try thinner maybe 3/16 and 1/8 to see what happens, having never done this before I should have tried a few test pieces of different sizes right out of the gate. It easy to do and I will try again. As I bent them around the mold I pulled hard to stretch the 1/4 x 3/4 WO around the mold. I'm pretty sure the temp inside the box was over 200 deg. eached strip was so hot I still have the reminder of the heat burning through the glove on my hand.

I reread the article in WB from Pert Lowell Company, I think I now understand the reason for the detergent but I haven't figured out the glycerine yet. The soap will allow the wood to slip against itself after it's taken off the mold and reshaped back together for bolting or rivetting it is very hard to get it back to original 5.5" size because of friction.

Does anyone know what glycerine does in bending hoops.?

One big mistake be that I made during this first attempt might be that once I compared my oak is that I used red oak I'm not sure if it bends as well.

I did some more research "I love google" red oak has a porous end grain whereas white oak does'nt have the porous end grain, I checked my oak and sifted through the supply even under a magnifying glass the white oak end grain appears very tight without the longer tubular cells.

I would assume that lack of long tubular cells is what makes white oak more rot resistant.

I won't be mixing my whites with my reds any more.

Something else I recently realized is that Red Oaks must be guzzlers and will drink up any old swill while White Oaks must sippers and prefer savour finer brands of nourishment.

Rufus

[Wooden Boat Fittings]

.
Sailor, I'll happily take your word about white oak -- I just have no knowledge of it at all.

Here, if I were to make hoops the traditional (Pert Lowell) way, I'd probably use oregon. But I'd still want to use 1/8" rather than 1/4". But in fact we generally cheat and make our hoops from marine ply. (Please don't tell anyone this -- it's a trade secret.)

Mike

[Chris Gerkin]

I have found steaming air dried oak much easier that kiln dried oak.

[Vinny&Shawn]

Air dried wood is a much better candidate for steam bending, for ten inch hoops I used a robust 1/4" ash straight grained no knots.
You can call Ralph Johnson at Lowell's shop,I think he might shed some light on your project, We had a good talk with him at the Portland boat show. He does not use a mold with a nok in it just round. I would also like to know what the glycerin is for, can't remember if it came up in the conversation.
Your steam box needs a small escape route for the steam to operate properly, this needs to be on the opposite end from the inlet. And no matter what you should have help and work swiftly,with a plan.

[bruce w]

making small hoops out of oak i use a old car seat belt ,fold it over the end of the steamed strip ,jam it in the jig with the strap on the outside and keep a pull on the strap and pull it round in one steady move walking round the jig, then wrap the end of the strap around finished hoop ,it helps to stop grain lifting.

[slidercat]

I'm curious as to why folks use mast hoops on smallish boats. I would think that individual robands of slippery line would work better in most respects. Roband length can be easily adjusted to tune the sail, and they don't bruise the mast. Educate me, please.

http://slidercat.com/blog/wordpress/wp-content/uploads/2009/03/sundog.jpg

[Vinny&Shawn]

[quote=slidercat;2147303]I'm curious as to why folks use mast hoops on smallish boats. I would think that individual robands of slippery line would work better in most respects. Roband length can be easily adjusted to tune the sail, and they don't bruise the mast. Educate me, please.

Mast hoops verses rope has been discussed in another thread and I think the consensus was for larger working boats and offshore or heavy weather sailing,hoops are stronger. Smaller craft and inshore do great with laced sails. Hoops do provide a secure ladder for going aloft in a pinch,or to do repairs. We leather our hoops to prevent chafe.

[slidercat]

When I think of laced sails, I think of continuous lacings, which have their drawbacks, compared with individual robands. With modern cordage, it seems unlikely hoops would be stronger than individual robands, but I don't really know the arguments. In my new boat, I'm using 3 mm Dyneema standing rigging with a breaking strength of over 2000 lbs.

I get the impression that a lot of mast hoops are made for nostalgic reasons, and there's nothing wrong with that.

[RT MAN]

I added a strap to the mold with any luck it will help eliminate cracking and splintering.

After a bit of research I discovered why Pert Lowell used Glycerine I believe it is to soften the fibers to help prevent splintering during the bend.


http://s46.photobucket.com/albums/f118/Alerion111/th_Moldwithstrap.jpghttp://s46.photobucket.com/albums/f118/Alerion111/th_Moldwithstrap2.jpg

Rufus

[RT MAN]

Ok I give up I must be doing somethng wrong 10 red oak strip start the pile of waiste

Now another 10 white oak strip have been added the first pile of waiste.

Even with the strap the strip seem to keep breaking. .

Steam box temp maxed out at 185*
I bent the strip fast enough before it cooled to much less the 1 minute maybe 30 seconds to full bend.

I'm using kiln dried wood soaked for several days. (5)

The WO might have had a bad grain run out which I think might be cause of this last disaster.


I will have to search for some better wood and also figure how to my steam box tempurature up 228*