Restoring a Tum27

[Tumlaren]

G'day,

Just purchased an old Tumlaren 27, built in '49 in Tuncurry, NSW. Apparently she has spotted gum deckiing, but the previous owner has painted over them with that peach coloured non slip deck paint. I want to strip them and leave them exposed - I am unfamiliar with spotted gum - can it lay exposed or does it need to remain painted?

[Daddles]

Welcome to the mob mate. I'm sane today, Midge is busy and the Wild Dingo has gone bush for a fortnight ... so you're safe :D

I won't even attempt to impose my ignorance on this question.

How about a few pictures - boat goes a long way here.

Cheers
Richard

[bitingmidge]

Grumble grumble...Qantas's website is down again, and I've got to fly out first thing in the morning but can't book my seat.... oh sorry, what was the question again? :rolleyes:

Sounds like a great project, but a bit of work to keep her right! Don't forget to post heaps of pics on this thread to keep us enthused!

Spotted gum: durability class 2 - highly resistant to decay.
http://www2.dpi.qld.gov.au/hardwoodsqld/7581.html

I don't know for sure, I haven't seen one exposed that I can recall, but that's not to say they don't exist in trawlers and so on. There are a few clues to durability, the first one being: if the spotted gum was suitable as an exposed deck, the old codgers probably wouldn't have covered it in the first place, or it was exposed and started to leak all over the shop, and they got tired of caulking it.

I know that spotted gum rubrails on a few steel trawlers I knew ended up painted because they kept leaching tannin for ever.

I think it's a fairly safe bet that when you poke under the pink deck paint, you'll find either canvas, or if not, that someone has replaced the canvas with dynel or fibreglass as a sealer.

I'm an old fashioned girl myself, and love caulked decks; as long as they are on someone else's boat.

If you find that exposing it is ok, in a boat that old you will have to recaulk it at least, and I'd be thinking very hard before I took on that commitment.

Are there any leaks at the moment? What does it look like from below?

Cheers,

P
:)

[Boatmik]

I have spent a lot of time lusting after Tumlarens - half your luck!

Fast, incredibly seaworthy - and gorgeous.

When the Catboat I did some work on was launched at a classic boat regatta - a Tumlaren ran away with the honours.

Here is the culprit.

MIK

[Tumlaren]

Thanks for your help fellas. No photos available as yet. No leaks as yet - I've checked her three times in the last four days. I'm going to expose a small section of deck to check its condition and then move on from there. the spotted gum specs on that forestry site (thanks bitingmidge) say that the timber is commonly used in decking etc so it may be alright.

Cheers
Daniel

[jmk89]

Spotted gum: durability class 2 - highly resistant to decay.
http://www2.dpi.qld.gov.au/hardwoodsqld/7581.html

Is this a first? New South Wales and Queensland governments agree!:eek: :D
The technical publication from State Forests of NSW, Timber in Boatbuilding, has spotted gum as a recommended timber for clanking and decking. It mentions that it is among the heavier timbers (1100 KG/cubic M) and also indicates that it has very high minimum strength values both as green and also as clear seasoned timber.

BTW, although last revised in 1996, the publication is definitely worth getting.
Here is a link to the State Forests' publications price list:
http://www.forest.nsw.gov.au/research/publications/res_priceList2005.pdf

[Ecca]

Spotted gum is in my opinion far too heavy for the deck.
If you dont like the ply/dynel or glass option and can't afford teak[ if you can get decent stuff ] then use queensland white beech. It does move a bit with moisture changes and is not the easiest to glue but seems to work OK with Sikaflex in my experience.
Tumlarens are beautiful boats and deserve the best.
Remember this, you are not the owner but the Custodian. If you keep that in mind whatever you do to the boat will help it survive many happy custodians.
If you look in Bootle's book Wood in Australia there are references to Jarrah and Karri for decks. Way to heavy for a Tum27.
Celerytop from Tas is another option although still a little heavy.
Thats my input, I dont ask for "boat "[ Saints preserve us] I hope you do a great job and that the Tum will live on
regards Ecca

[Boatmik]

Hi Everyone.

Laid Decks . . .

(Sorry guys - I have got enthusiastic about things again - but I do get to the chase later)

There is a really good set of arguments for going with a plywood deck, but before I cut to the chase I want to give you a little bit of history.

One of the very greatest of the classic yacht designers was L Francis Herreshoff. He was the son of Nat Herreshoff but had very much his own design direction.

He designed dozens of boats that are classics - that will hold you spellbound with the sheer gorgeousness of every curve and line. And they sailed like rockets too.

On the racing side - he virtually gave up designing racing boats after he destroyed the Universal Rule by driving a truck through the rules.

The universal Rule boats are the various letter classes. The J Class that used to race for the America's Cup. Anyway all the hot designers worked in the R class (about 45ft long).

When L Francis came along with his "Live Yankee" - rotating wing masts, Super lightweight hull with over 80% of the weight in the ballast keel, sails with two surfaces (ie one surface attached to the right back corner of the mast, the other attached to the left back corner) forming a thick, efficient airfoil the boat's performance was so high that it outdated the existing fleet instantly.

Oh, by the way - wing mast, double luff sails, super lightweight hull - this was in 1929.

So they changed the rules and LFH dropped out of the racing scene soon after.
_________________________________

Plywood

OK - LFH was around before plywood. His designs are among the most sophisticated traditionally built boats ever conceived.

He HATED plywood with a vengeance - he called it "stinkwood" because os the smell when you cut it with a powered saw. The only thing that he hated more was fibreglass - he was one of the first if not the first to call it "solidified snot"

But by the end of his life he was happily specifying plywood for decks and bulkheads.

He had to concede that it has a number of great advantages.

1/ Plywood is so structurally superior. Having the deck of one piece allows the significant rigging loads to be carried in it as a single beam. There are huge compression loads carried in the deck as the two shrouds on either side of the boat try to squeeze the boat together. The same thing happens between the forestay and the mast - the forestay is trying to pull the bow of the boat up and back - leading to huge compression loads as the deck resists.

The problem with laid decks in a structural sense is that to handle the lateral compression loads there is a huge "squeezing" effect on the caulking. As the boat manouvres around this varies enormously with the caulking between the planks going through cycles of being squeezed and released. This is very tough on the caulking (fibre jammed between the deck planks and then sealed by putting tar (or a more modern polyurethane sealer) over the top between the planks.

The twisting of the boat (as the mast pulls it one way and the keel pulls it the other) also causes significant tensile and shearing loads between the planks.

But the squeezing means that over a few years the caulking becomes compressed, the deck starts moving more and the tar or other sealer gets pulled and pushed in all sorts of weird ways and finally starts splitting.

The deck leaks.

The old way of dealing with it was to canvas cover a traditional deck. So you would caulk and pay (tar seal) it then paint on a heavy coat of white lead paint and lay canvas down over the top and paint it. This increases the life as the canvas soaked with paint is quite waterproof - but the cycles of compression will result one day in the canvas tearing. Or it just becomes worn out from people walking on it.

When fibreglass arrived on the scene it became popular to use fibreglass and polyester resin instead of the canvas. It is a slightly better solution because the glass can sustain tensile loads (if it is thick enough - which causes problems with expense and weight) and the old polyester resin doesn't stick to wood very well - see ... http://www.storerboatplans.com/Faq/Epoxyvspolyester.html (http://members.ozemail.com.au/%7Estorerm/Faq/Epoxyvspolyester.html).

With a properly installed ply deck - it is all one piece - so all the loads - tensile, shear and compression can be carried easily without the problem of having to transfer the loads across many joins that are prone to movement.

2/ Plywood is cheaper - it is starting to become hard to find timber suitable for decks at reasonable prices - you should use quarter sawn fine grain stock (all the woodies are salivating right now). The quarter sawn stock means that the timber will swell and shrink evenly as the moisture content changes.

Ply is much cheaper and more available. Also because of its structural efficiency the thickness of the deck can be reduced - reducing cost and weight.

3/ Plywood is easier - because it covers such large areas it cuts the amount of labour enormously. Using modern epoxies you can eliminate all screws and nails too - and just use some temporarily to hold things in place while the glue sets up. This cuts cost and also reduces the number of points where water can intrude into the timber structure.

Eliminating fastening also makes deck repairs a dream. Just set a router to the thickness of the deck ply and cut out any damaged sections without the slightest bit of damage to underlying structure. FANTASTIC.

Eliminating fastenings ...
http://www.storerboatplans.com (http://members.ozemail.com.au/%7Estorerm/Faq/Epoxyvspolyester.html)/Faq/screwornot.html (http://members.ozemail.com.au/%7Estorerm/Faq/screwornot.html)
________________________________

A couple of further discussion areas.

When not to use plywood - It depends on your view of the boat and the boat's history. If the boat is historically significant or you really like the idea of keeping the boat in a traditional form - then do it! It will mean more maintenance and might mean a bit more inconvenience - but if you LIKE traditional boatbuilding process - that is the way to go.
____________________________________

What not to do with ply - OK - this is a lesson for the housebuilders amongst us...

NEVER - EVER - JOIN PLANKING OR PLYWOOD TOGETHER OVER A BEAM OR A FRAME LIKE YOU DO ON A HOUSE.

ie some people join the ply or deckplanks and butt them together by having the end of each sitting halfway over a deckbeam or frame. This is not adequate for boats

If you deckbeams are 50 mm wide and are spaced 400mm apart what happens is if someone puts their foot between the beams then the edge of the beam that the plank rests on becomes a fulcrum and as the deck is pushed down by the foot and the fulcrum takes the load the edge of the plank is levered up from the surface of the deckbeam. The mechanical advantage in this case is 400/25 - or 16:1 so you will easily break the glue join or pull out any fastenings.

You need to use properly designed scarf joins (minimum of 6 to one glued with epoxy) or butt straps (20 times the plywood thickness (so 9mm ply needs a butt strap 180mm wide glued underneath) or for planking a properly designed and installed butt block (you will have to do some research - McIntosh and Rabl's books are very good - also there have been a number of articles in WoodenBoat magazine over the years).
_________________________

Using good quality Marine Ply or planking timber. The Tum is a fantastic boat - great, fast sailor - excellent heavy weather boat. She is going to be around for years. Because of her narrowness there is not a great deal of material involved in the decks - so get the best quality marine ply that you can. She is going to be around for another 30, 40, 50 years and cheap ply and other low quality material will come back to haunt you - and faster than most people think too.

The deck should be sheathed in fibreglass fabric (NOT chopped strand matt) using the same good quality epoxy (Bote Cote, WEST, System Three and some others in the same price range) that is used for gluing the ply in place.
_________________________

You can make a ply deck look like a traditional laid deck by gluing planking over the top. For a boat like the Tum it is important to not go too heavy - the boat will perform much better and be dryer when sailing in a seaway. See a copy of "The Gougeon Brothers on Boat Construction" - (big book just reprinted) or get a copy of a cool little pamphlet put out by WEST "Wooden Boat Repair and Restoration" - it is about $10 with heaps of useful information.
_________________________

Depending on the deck frame spacing 9mm ply with 10oz (300gsm) glass (or 450gsm bi-axial) over the top would be adequate for the TUM. It ends up looking like canvas decks

If going for a timber veneer laid over the ply it might be good to try and locate some 8mm ply. The veneer should not be too much more than 4 or 5 mm after sanding.

see
http://www.storerboatplans.com (http://members.ozemail.com.au/%7Estorerm/Faq/Epoxyvspolyester.html)/Faq/Sikaflexteakdeck.html (http://members.ozemail.com.au/%7Estorerm/Faq/Sikaflexteakdeck.html)
_________________________

In fact have a look over my FAQs on using epoxy with boatbuilding
http://www.storerboatplans.com (http://members.ozemail.com.au/%7Estorerm/Faq/Epoxyvspolyester.html)/Faq/faqindex.html (http://members.ozemail.com.au/%7Estorerm/Faq/faqindex.html)

Best Regards
Michael Storer

[Daddles]

Mik has a dream. One day, he will write a post that occupies an entire page of the forum :D

Richard
welcome home mate - want to hear how Redback sailed on the weekend?

[STEPHEN MILLER]

It was painted probably to reduce maintatinance work. Guy I know has a Tumlaren is stripping back all the bright work and oiling it because he is sick of covering up the boat to preserve the bright work. Strip it back ,if its in strips, sand in back dig out old sealer between strips, use sikaflex in betwwen make sure you use sikaprimer first and masking tape all planking before putting sikaflex in to make clean easy. Spotted gum is a hardwood you could oil it after putting sikaflex in with Deks Olge or similar if you were concerned about durability

I HAVE A DREAM A POST FROM MIK WHERE HE GETS TO POINT IN UNDER FIVE LINES:D

[erogs]

Some interesting info at this site http://www.penofin.com/tumlaren.shtml it might be also worth contacting http://www.endeavourmarinetimberfinishes.com/aunz/intro_aunz.html for info on finishes.

Cheers

Steve

[Boatmik]

1 Howdy Stephen and Daddles,
2 I am afraid that both of you are in for a disappointment. With the above
3 post I am only 3 characters off the maximum allowed. Very pleasing
4 result! And the great stinking joy of this boatbuilding, design and history
5 thing is just too, too good for me to cut back much at all. Maybe some
6 OOOOOOOOOPS
7 people find my particular angle as interesting as I find both of yours!!!
8 Best Regards
9 MIK

[Daddles]

Dunno Mik. You had to use character returns to get those lines in :D
Didn't realise there was a limit on the size of a post, though it shouldn't surprise me. Only 3 characters eh?

Isn't it fascinating how history affects the way things are done. Your posts are certainly giving me more insights.

Richard

[Boatmik]

So Daddles ...

How did Redback go on the weekend - as if you need an excuse!!!?

MIK

I'll be looking in the Redback Has Wings thread.

M.

[Boatmik]

Howdy Stephen,

Quite right about the oiling. The only downside of it is when the boat is kept in an area where there is industrial fallout or lots of car traffic nearby.

I used to work in Rushcutters Bay - just down from Kings Cross in Sydney - around 4 miles from the CBD with a couple of main roads running by.

We found that oiled surfaces tended to turn a black colour over a couple of years probably because of their slight residual stickiness.

Though the Decks Olje system has the #2 to use over the oily #1.

MIK
sorry again - six lines of text :-) Sometimes there is not a lot to say on a topic :-)

[Boatmik]

Help Dingo

If staying with the laid decks wouldn't they have to be caulked with oakum or cotton before thay are payed (even if it is with that newfangled polyurethane stuff)?

I guess they could have been originally edgenailed and glued? Then if the glue is OK they could just be re-payed with the Sika

MIK

[STEPHEN MILLER]

Mik used have have our boat moored Port Adelaide Sailing Club next to the Birkenhead Bridge contiuous diesel fallout and road grim with bridge being above your boat was shocking now where at St Kilda the boat certainly stays cleaner apart from swallow crap. I used Endevour oil on the gunnels and changed to Deks Olje think it does a better job used it on the hand rails to but have them off at present and I am going West System 107 then varnish over the top the rails are design for easy removal to revarnish off the boat on regular basis. Your doing well Mik with the size of your post all your imformation is always a good read for ideas except sometimes I think I can hear Richards brain overloading from this side of town and wait in anticipation for the explosion.
:D

[Daddles]

sometimes I think I can hear Richards brain overloading from this side of town and wait in anticipation for the explosion.
:D

BANG

[STEPHEN MILLER]

Can see the MUSHROOM cloud from up here good thing theres no wind so the fallout will stay where it came from:D

[Nifty1]

Just a note about spotted gum - we have it laid as a house deck and it seems pretty stable. I also used it for rubbing strips on an old cruiser, got it in about 8m lengths. It can have an obstinate grain, which makes it difficult to plane or machine unless tools are very sharp. Heavy, strong, and accepted a sheerline bend with a bit of persuasion.

[Rik]

Hi Everyone.
or get a copy of a cool little pamphlet put out by WEST "Wooden Boat Repair and Restoration" - it is about $10 with heaps of useful information.

Michael Storer


Well Michael, you are a generous man. In the 24 hours since I picked up my "new" boat, a beautiful old plywood NS14 with the sail number 2587 (and the mysterious letters BMFG on the stern) I have gone through many many pages of your website and many of your postings (and others on this forum). Man does this newbie have a few things to learn if that old girl is ever going to feel water on her hull again.

I would like to find this pamphlet that you've referred to but I can't find it anywhere, including the Westsystem sites I've found. Could you please post a URL or other address for someone who distributes it.

Thanks, Rik

[Boatmik]

Howdy Rik,

I think the F is an expletive. It is in the right place.

Would be great if you can start a restoration thread and post some pics. As you don't intend to race it simplifies things considerably.

Did you get a mast and sails? Foils and boom?

Those ply NSs are a delight which I have mentioned elsewhere.

The advantage is that if you put up some pics and write about what you think are the problems (with specific photos) then I and others can offer suggestions and call each other all sorts of names!!!

Actually it has seemed to work quite well. There are a couple of quite lengthy threads about restoring specific boats on this site.

My FAQ has some suggestions but it takes a bit of experience to know where to start in amongst all the possibilities.

Best wishes
Michael