what to do with the deck.

Hi,

Your samples turned up today. The decking timber is definately white beech or "Gmelina leichhardtii" according to my K R Bootle wood book, there's apparently some other Gmelina's that are similar/same name. Not so easy to get Australian sourced but seems to come from Solomons- PNG & Fiji now.
It's got the classic buttery appearance & fine silica streaks also typical, very easy to work but smells a bit like dirty socks. Probably my favourite decking material......Love the contrast between weathered silver/white timber & pitch or sika.... looked after a km or three of it on the James Craig.... the tv in family room is on an honduras mahogany cabinet with beech overlay decking & best of all my pivotal career decision moment was on the riverbank of the Richmond sitting on the coachhouse of a great little 30' yacht under construction- Beech decks, Spotted gum timbers & keel etc with flooded gum planking... at about 14.5 years old having a cup of tea whilst our hosts had a "smoke" when some georgeous local girls came around to visit... all beads & cheesecloth & full of natural lovely wonderness.... that settled it! Boat builder or Hippie!.... so I love beech decks
The "top plank"/sheer plank? is a bit tougher, without taking the paint off it would be any guess, so tomoz I'll knock off the paint, sand & present to the panel at smoko or lunch.
Regards from Jeff.

 

Thanks for the help jeff. A wealth of info as always. Thats the deck planks sorted . It will be interesting to find out what the sheer plank is. I was told the hull is spotted gum to the waterline and oregon above. I was surprised when I found the sheer to be hardwood. I didn't expect to hear from you so soon with the floods and power outages up your way.

 

Interesting exercise today........
Aussie hardwoods- eucalypts vary in colour-texture-density in region/climate, soil. My career in Shipwrighting has been about a third each on timber-steel-composites. I was about 85% on Spotted when I looked at the end grain of your sample last night, I've used a fair bit over the years, first up this morning I rubbed the paint off with a linisher, colour was pretty typical brown with very slight greenish tinges with some darkening around old fastenings- the tricky thing is splitting characteristics- a bit too easy & specific gravity calced right on 95% & end float test same which seems low to me, spotted is often a sinking timber although I didn't check MC as meter was at home, your decking sample just showed 12%- 17 %.
Unfortunatly I worked through smoko & lunch but caught up with four other shipwrights & a shipwright/bridge & wharf chippy & one curator, everyone was on eucalypt once in natural light.. one on brushbox, two younger/less time in trade on unsure & two senior on spotted- one probably but feels light, one as presented was oh, spotted- whole career in timber vessels, unfortunatly our most senior shipwright wasn't in today.
So really pointing at spotted gum, some minor details lead away but could easily be accounted for in regional variations & three different genus are termed spotted(amongst other terminology) also apparently, my example at home is a offcut of 8x2 with fiddlback featuring & grain interlock that we use as a chopping board- sinks in the sink, MC just tested at 13/14-16%.
Given the East coast heritage & very common usage in boatbuilding, the stated material usage in the vessel, various opinion representing a couple hundred years in marine industry/shipwrighting....... it's prolly spotted gum...

Just remembering a block of land I had on NSW South Coast- Sanctuary Point in "Mountain Street- the lowest flattest swampiest street in the town- maybe it pointed towards a mountain somwhere, built my first house there, I got a bloke in to look at clearing the house site, he put in a pretty cheap price, the spotted gums had a good 60 odd feet of dead strait trunk with branch ball of about 30 foot on top, I come along for a look at the operation, he sidles over, oh sorry mate a couple of extras came down...... & straight to the mill...... Good job, I'd dropped one & woke up that it needed someone that knew what they were doing........
Jeff

 

Thats great to know. Thanks again jeff. I have found a supplier called marine timbers in melbourne who supplys spotted gum and clear oregon(douglas fir). I will pick up what I need this week and get the job finished. I need to get out sailing on the lakes for a bit before replacing the deck. I have found boatcraft Pacific to be a good source for the nails and roves. Quick postage and reasonable prices. I have also purchased a bmw/hatz. 30 hp engine to replace the tired old 4107 perkins. I love making extra work for myself.

 

My oregon planks are 30mm thick x 90 mm wide. Will they bend slightly when fastened to ribs or will they be to stiff. I can throw them in the steamer if needs be.

 

Hi Brendan,
do anything that makes your job easier, some times a little extra effort in steaming will pay off well- my old maths teacher at school had the terrific saying "the lazy man works twice as hard".
definatly worth the effort- the risk is with your short plank repair is that you flatten the area by offering in the 5-6? straight planks into the same zone. You could set up a jig to bend on that represents the curve plus some for spring back although we will usually just steam & clamp over the adjacent plank- & will just slip in some 1/2-3/4" packers to overbend accounting for spring back, also sometimes clamp over a wedge at each end to over account for twist & springback maybe 1/2" to zero.

Regards from Jeff.

 

Thanks again jeff. I will fire up the steamer and get bending. I already have the jig made and a sample off the boat with the bend in it. Last thing I want is a flat patch.

 

Gotta love those steam boxes

 

I do except for trying to steam old hardwood the other week. What a mission that was.

 

Update. I have not done a lot for a while due to work commitments. I did get the 1st section of plank in and all the new frames riveted 3 planks deep below the repair. I am going with butt blocks rather than scarfing because I don't think I have the skill to scarf planks while the boat is in the water. (Sorry jeff. I know you recommend scarfing ). Is there any advantage to fit butt blocks out of oregon rather than 1" ply. I thought ply might be stronger .

 

Brendan, I have not been following your thread for a while but thought id offer what I have learned from observation on a number of planked boats I have done repairs on. I should point out while I am not a specialist in carvel boats, having built dozens of cold molded and composite boats im the closest thing to it in our region so often get to repair the few planked boats left around here. I actually consider it an advantage to not be mired down in repairing things in the traditional ways just because " that's the way its always been done". Scarfing the planking is a good example of a better way of joining planks together but I don't think id do it either on old salt soaked planking especially doing it with the boat in the water. Butt blocks are an adequate method but what I have found is that many old but blocks are split from the screws so what I do to ensure that this does not happen is, rather than just use a piece of wood I laminate up a 3 ply plank of appropriate wood long enough to get all my blocks out of, homemade plywood if you will, of,say, 3 plies of 10mm, bevel the top edges so water wont lay there and then paint all surfaces well. You now have a block with cross grain strength to resist splitting. The other thing I do is use machine screws with nuts, flat washers and lock washers instead of wood screws. Again, less likely to split the wood and stronger over time. Usually silicone bronze as thets what the other fasteners typically are. You could probably use hot dipped galvanized fasteners if appropriate. Ive seen way too many split butt blocks to ever consider single ply, once the block splits the screw loses much of its holding power. Most blocks ive replaced will have maybe 5 screws each side of the join so often there will be 4 screws in a row over the length of the block all contributing towards splitting along a grain line, just plain dumb imho. We have the adhesives today to do better. You can bed the block with appropriate modern goo or roofing tar works well too but make sure you have 100% squeeze out so you know there will be no water between the block and plank.

Steve

 

Great reply. Thanks steve. I can pick up a couple of 10mm oregon floor boards to make blocks as you describe. 3 x 10 mm will follow the curve of the hull a lot better to. My boat is all copper nailed which is what I was going to use for the butt blocks but silicon bronze screws and nuts is a better idea above the water line .

 

Ah yes, riveted, that would also be better than wood screwed. I like the silicone bronze machine screws because you can draw everything together so easily plus of course they don't cleave the wood apart along the grain, but then neither does riveting. What gauge copper nails are used and how many each side of the plank ends?

Steve.

 

I think they are 10 guage with 2 per plank.

 

I have just cut 3 oregon planks. 30mm thick. 1960mm ,1600& 1300 long. I have clamped each down with chocks under the ends to put a bend in them. Tomorrow i will fit them on the boat. They seem to bend easy without steam. Am i doing the right thing here. The planks don't seem to be under any stress.