Douglas Fir for planking

[anne]

I am repairing an old Norwegian sailing trawler built of pine on pine. The only available wood around is Douglas Fir, mainly it is for planks above the water line some of which will need steaming for the curve on the stern.

Any opinions on using this material I would be glad of. The larch available in Ireland is -----!
Anne

[alan white]

Choose quartersawn stock, not flatsawn, and preferably air-dried. It (quartersawn) will expand/contract least. Fir should be fine. Many boats such as the riginal S&S Lightning have been planked in fir.

Concur.

Douglas Fir is a proven choice and probably better than the pine it replaces.

Regards
Richard

[SamSam]

From what I can find, it says Douglas Fir is a poor choice for steam bending. ?? I've used it for gunnels and was able to slowly bend it to shape, but it was sort of brittle, and when it broke it split and shattered.

Originally Posted by SamSam

From what I can find, it says Douglas Fir is a poor choice for steam bending. ?? I've used it for gunnels and was able to slowly bend it to shape, but it was sort of brittle, and when it broke it split and shattered.

Interesting observation Sam.

I never used Dougas Fir myself, therefore cannot comment from first hand experience. And my databases do´nt mention issues (but that does not mean too much).

Regards
Richard

[dskira]

Originally Posted by SamSam

From what I can find, it says Douglas Fir is a poor choice for steam bending. ?? I've used it for gunnels and was able to slowly bend it to shape, but it was sort of brittle, and when it broke it split and shattered.

I suppose you are talking bulwark? Keep comming slowly from the stem rabbet to the aft, use stanchion (provisonal or permanent) and on the outside of you plank keep an other plank of small thickness on clamps with larges throat, bar inside , just to keep the outside of the fir.
It is ok to steam but the result as you say is not the one on oak. But for a bulwark it can help a little.
Two day in a bath of kerosene will also help. But the wood as to be submerged, so the tank must be quite large.
I use this system and work quite well. The kerosene has to be changed every two month due to the fact it become gummy.
Be gentil, take your time, and it will follow your shape all the way.
Patience and time is the essence.
Fir is a wounderfull wood, full of surprise. I used it often when available at a good price. It seams quite pricy now, but worth every dime.
Good luck
Daniel

[dskira]

Originally Posted by anne

I am repairing an old Norwegian sailing trawler built of pine on pine. The only available wood around is Douglas Fir, mainly it is for planks above the water line some of which will need steaming for the curve on the stern.

Any opinions on using this material I would be glad of. The larch available in Ireland is -----!
Anne

It is Douglas fir? some fir from Europe are called Douglas fir and althought great are hard to work with.
If its a real douglas fir, without a doubt you will find it is a great wood for your project
Read if you want what I said to Sam, it is the same for you, but your supports are the frames, so easier.
The splines going straight under the nails when you work this wood is commun and very painful. Becareful with jointers, fir can be very rebell to maachinery.
Go easy, patience, and time. A tree take a long time to grow, it take a long time to work with.
Good luck
Daniel

[SamSam]

The end of the plank where the bend is needed could also be split with a bandsaw. Like if the last 6' of a 14' long 2" thick plank was too stiff, the 6' part could be split to two 1" thicknesses and epoxied when bent.

[dskira]

Originally Posted by SamSam

The end of the plank where the bend is needed could also be split with a bandsaw. Like if the last 6' of a 14' long 2" thick plank was too stiff, the 6' part could be split to two 1" thicknesses and epoxied when bent.

I don't know if you allready tried it.
It is possible to do it with seam bent frames (without epoxy) but for planking ? I never heard. It seams odd to put epoxy in between on a carvel fashion built and to have a 2" planking the vessel must be quite large around 90'. For a let say 40' the planking will be 1 1/8" so I dont see the possibility to split in two.
At 30' the planking will be 7/8". So classic way to bend is more apropriate.
Now the bulwark is normally the same thickness than the planking. You can have a whale plank slightly thicker, but it will be the only one.
I am talking scantling for a yacht. A fishing vessel the scantling are quite differents.


Daniel

[SamSam]

I'm just replying to the original poster, I'm not doing it. All the info is in the first post. An "old Norwegian sailing trawler" sounds like a fishing vessel. No length is given, I assume it's largish.

The planking available is Douglas Fir, some of which will need steaming for the curve on the stern. I could only find info that said DF was a poor choice for steam bending. I know it's stiff and brittle, and if it's been kiln dried, I think it makes it even harder to steam bend. I could be wrong. I also have no idea of the amount of bend needed.

It's for above the waterline, which would seem to lighten it's responsibilities somewhat. It would seem very easy to bandsaw a 1 1/8" thick plank to two thicknesses of a bit under 9/16", in the area of the bend, and it would make that portion more flexible, especially with steaming. If the boat is carvel planked as you probably correctly assume, I am not saying to epoxy the edges of adjoining planks together, but the split in the individual plank, which more or less makes it a laminated plank.

[dskira]

Originally Posted by SamSam

I'm just replying to the original poster, I'm not doing it. All the info is in the first post. An "old Norwegian sailing trawler" sounds like a fishing vessel. No length is given, I assume it's largish.

The planking available is Douglas Fir, some of which will need steaming for the curve on the stern. I could only find info that said DF was a poor choice for steam bending. I know it's stiff and brittle, and if it's been kiln dried, I think it makes it even harder to steam bend. I could be wrong. I also have no idea of the amount of bend needed.

It's for above the waterline, which would seem to lighten it's responsibilities somewhat. It would seem very easy to bandsaw a 1 1/8" thick plank to two thicknesses of a bit under 9/16", in the area of the bend, and it would make that portion more flexible, especially with steaming. If the boat is carvel planked as you probably correctly assume, I am not saying to epoxy the edges of adjoining planks together, but the split in the individual plank, which more or less makes it a laminated plank.

I never did it, but it can be something to try.
It will a sort of double longitudinal planking in a way.
I am not sure epoxy will be necessary due to the fastening on the frames.
A classic "goop" can be more in tune with the wood tendency to move, and far less expensive.
Any way if you do it, tell us the result, it will be interresting.
Daniel