what to do with the deck.

Plywood isn't the best frame material, as a huge percentage of the grain, is running the wrong way. In a laminate stack with thin plywood, the veneer count helps, but the end result is weaker than a solid wood laminate of the same count and dimensions. Then there's the fasteners into end grain issue with plywood sisters, not to mention moisture exposure.

To me, if you're going to the trouble of bending in several layers of 1/8" plywood, it might as well be solid wood strips instead.

Rig a 2x12 to hang over the side of your boat at the work area. Maybe two 2x12's so you have some footing to brace against. I've done it with length of line in a pinch, but something more substantial if you'll need it for several days. A few 2x4 cleats under the 2x12's and some 2x4 brackets to hold it to the deck and/or hull sides.

The single part polyurethanes work, though I don't like them much. They cost more per ounce than epoxy and the foaming thing pisses me off and I don't trust it not to let in moisture.

 

Thanks par. I will stick with the hardwood strips , I was curious about the ply but your right. There is no difference in time anyway. Purbond is supposed to work well on our hardwoods where epoxy sometimes struggles to bond .

 

I've never had issues with hardwood bonds and I use teak, white and live oak regularly. The key with some of these is the pretreatment, usually to remove oils and/or tannins. A quick scrub with solvents, will get the worst and the goo is ready to apply within minutes.

 

Will acetone do it. I have a 20 lt drum in the shed.

 

Depends on the wood species, though acetone is often in the mix, for several reasons. One is to speed up flash off times, second is to drive moisture out and it also sanitizes the surface and just below, killing beasties, you'd rather not get a foot hold.

 

Made a start on the frames today. Put 2 batterns on the outside with spacers to make up the plank thickness. This idea worked really well. Now i can see the shape of the hull. The 3 frames in position are held by screws . The copper nails and roves have been ordered and should be here soon. There are 2 more frames to be fitted but I am still steaming the pieces for them . I found steaming a slight curve 1st made all the difference. There is only slight pressure on the batterns . Without steaming I think the frames would push the batterns out. Thanks again to everyone who has been advising me on this repair. P.s jeff the frames are an aussie hardwood but we could not tell what it was. It is the heaviest wood I have ever picked up. The screws are only there until the nails go In.

 

I've had a close look at that timber, species wise definitely either Didgrow or Wasatree...................

Whoever sold it prolly called it something like "forest reds" or "forest browns"....
Should be fine Aussie hardwoods are great, durability in boat structures has a lot to do with ventilation & drainage.

Looking good
Jeff.

 

Thanks jeff. My uncle had 2 3x3's of this timber In his redgum stack he makes furniture with. Neither of us new what it was.

 

Bit late maybe, but I've used that Purbond stuff to glue up blue gum. It failed in the joint - split away from the timber. And yeah, the timber was dead dry and very clean - I'd had it air drying for 8 years.

Epoxy, OTOH, the timber tears out, not the bond fails. I use a 2 pack 1:1 mix that's non-slumping for joints etc. Works really well. No better, probably, than mixing micro-ballons etc into runny epoxy, but a lot more convenient.

PDW

 

Not to late pd. Thanks for the reply. I normally use epoxy for everything but have heard it didn't bond hardwood very well. Now thats cleared up I will use it.

 

PurBond, like other glues of this type requires; fresh stock (the glue), good working conditions (temperatures/humidity) and lots of clamping pressure or less than desirable results can result.

 

Today I am going to steam a piece of hardwood for the deck beam . Its 4 1/4" x 2 " hardwood. Any ideas on how long it will take to soften. Its a pretty solid looking piece. I have been soaking it all night.

 

Please,.... don't bother. I have never seen steamed deck beams. Not saying it's imposible/never done, but they're usually sawn to shape, sometimes glued/laminated but that's heaps more work- more wastage-cleanup but prolly "stronger"
If you don't have the width it may be possible to glue the waste from the bottom to the top......... but easier & quicker to just mark the camber to full width material, set a circ saw to minimum depth required & cut "outside" the line leaving some "green" to work down to.

Jeff.

 

Sorry jeff I used the wrong words again. I mean the beam that runs fore and aft which the top of the frames fix to and the deck screws down on. The pic is upside down.

 

That's the clamp and it's common to have deck beams notched into it.

Steaming a big hunk of hardwood like that will take a few hours in the steamer and it's not going to be particularly compliant. Simply too big to manhandle.

Saw it to shape and if using epoxy use nothing thicker then 1 by stock. This means two pieces, glued face to face, sawn to the appropriate camber. See if you can find stock that has a complimentary grain curve in it, so there's less "runout".