bondwood speedboad under restoration

[Boatmik]

Bending wood is a crap shoot at best. I've bent a lot of it over the years and have a feel for it, which increases my success rate....

Everyone should frame PAR's reply above - it is simply the best summary I have ever read of the problems and solution.

Maybe delete the line about boiling alcohol - SOMEONE will try it (God save us from "Practical" men - who are always the ones who get into trouble).

But it is fantastic!

Cheers
MIK

[jellyhead]

thanx heaps AJ, will try that for sure, to secure the gunwale to the topdeck what would be the best method, to pre drill and countersink each strip and glue. i have brought this strong wood glue from the hardware that is a powder and you mix it with the liquid suplied or should i use something like no nails and screw. And with replacing the deck would structual ply covered with a water proofing membrain on the under side be ok or should i use a propper 5mm marine ply.

I would also like to say THANK YOU to everyone for there help, this is my first resore of a wooden boat and she means alot to me to make it look micky mouse. dont want to cut corners but money is always an object. My last boat was a 1962 bellboy half cab with a 55 chrysler o/b that give me nothing but headache after headache,

[b.o.a.t.]

to secure the gunwale to the topdeck what would be the best method, to pre drill and countersink each strip and glue. i have brought this strong wood glue from the hardware that is a powder and you mix it with the liquid suplied or should i use something like no nails and screw.

I have no knowledge of this glue so can't comment on it. This strip probably isn't a structural member, so any strong water resistant glue might be ok. Whatever you use ought to have reasonable gap filling properties to keep water & rot out. Whether you also use screws or not depends on how much tension is in the wood & how much you trust the glue. I used screws on the 2 under-courses to locate them while the epoxy set, and because I didn't have enough clamps. Then I removed them & back-filled all screw holes, covering them with the outer course. The only screws left in Teal are the ones holding on the inspection covers. As the strips are thin, there is little tension & marine epoxy is more-than strong enough to hold it together.

And with replacing the deck would structual ply covered with a water proofing membrain on the under side be ok or should i use a propper 5mm marine ply.

Structural ply (usually C/D grade) is a false economy.
Reasonable quality "pacific maple" BS1088 marine ply can be had for same or less cost than pinus crapiata exterior/structural. It will be stronger, lighter, have fewer blemishes, faults or voids, and will cost a lot less work to make it look good. Aust-made hoop pine marine ply is a lot more expensive but is stronger & stiffer. And guaranteed to AS/NZS 2272 - 2006 (which is in some respects better than BS1088).

Installing a waterproof membrane under a deck is moving into Big Boat territory & I'm not qualified to comment. Gut feel is that it is better to keep water out of the structure in the first place with a good coating system !

I would also like to say THANK YOU to everyone for there help, this is my first resore of a wooden boat and she means alot to me to make it look micky mouse. dont want to cut corners but money is always an object.

Use good quality materials. Overall it might cost you 20 -30% more now, but will last many times longer & save you big-time $$ long-term. I cheated with the inner courses of my gunwales & used cheapo pine. What little I saved then in time & money has cost me many times that over in increased maintenance & vigilance to keep it rot-free.

My last boat was a 1962 bellboy half cab with a 55 chrysler o/b that give me nothing but headache after headache.

Amen to that !! We had a 45 & a 70. Both were heaps of junk.
cheers

[PAR]

The powdered glue he's referring to is likely ureaformaldehyde (plastic resin glue). It's classified a type II, water resistant structural adhesive.

It isn't gap filling. It requires pretty strict adherence to temperature and clamping pressure requirements and it can't survive long if immersed. I use it in a lot of situations, but never in the hull or deck structures. Spars are often glued with it, because of it's pleasant glue line color. Because it requires lots of clamping force to insure a good bond during cure, the joints must be quite well matched.

I'd agree with BOAT in that the use of the best materials you can afford, is always a better way to go. In traditional boat construction, the hull usually has the best quality wood on the boat, for obvious reasons, it keeps your socks from getting wet. Use the cheaper stuff on the furniture, cabinets and other internal elements, where they can be painted or skinned with a veneer or other product for looks.

The use of a vapor barrier or other membrane isn't generally the way to go. It just traps moisture between layers of things where it can do more harm then good. Ideally, your seams and materials should be well sealed or arranged to permit moisture that may collect to drain out, either into the bilge where the pump can get at it, or over the side.

It's okay to let water into the boat. It happens naturally with splashes and boarding waves. Rain, leaking covers, spilled beer (a true sin and worthy a substantial flogging), etc., all permit water into the boat. It's okay and can be sucked up by the pump and tossed over the side. It's important to keep this in mind during construction. Nice big weep holes and free drainage into the lowest point of the boat. On most powerboats this means two pumps. One aft at the transom, so it can suck out any leaks while under way (up on plane) and one in the forefoot area. Typically the forefoot is deeper then the transom, when the boat is at rest, so a pump in this location is often called for.

[jellyhead]

You guys are awesome, my cogs are moving now.
6mm hoop pine sheets marine ply ordered, went and got two bildge pumps today, and the new bearers are in and waitting for the new floor to go down. i tell ya the marine clear varnish is so expensive nearly fell over in the shop...

the deck skelleton is in good condition, which i was suprised..to secure the ply to the top i was thinking of using 6gauge soild brass chisel head counter sunk screws...is this the way it i done or is the a special method to do this , the screws showing through the varnish is not a problem , i think it might look quite good but as i said i would like to keep it to the way that they were origanily built. i was told that my boat is a 1972 ramsey, but i'm not quite sure of that cause some people have said different such as , helmsman, stejcraft...will try to get some pics up and maybe someone might no.......

keep ya updated....Ash

[b.o.a.t.]

ONYA, Bloke !

I'd be cautious of brass screws. Unless excruciatingly well sealed, eventually the zinc leaches out of the alloy leaving you with a blue-white mush where the screw used to be. I rescued a hull from the tip one time, only to put it back a few weeks later once I realised every one of the zillion screws in it was cactus.

The old-salts suggest bronze rather than brass - slightly different compound -I think it has tin in it as well as, or instead of, zinc & is far less prone to corrosion.

Or a marine grade stainless steel.

cheers
AJ

[PAR]

Bronze is an alloy of copper and tin with some zinc tossed in sometimes to increase fusibility. Brass is an alloy of copper and zinc with a little tin added sometimes to increase hardness and /or change color. Lead is often added to both to increase it's ability to "stand" before a cutting edge.

There are many different "mixtures" of bronze, each having there place. Commercially available bronzes, found in fasteners are quite good.

Brass is the redheaded stepchild of the copper alloy family and only worthy of holding a picture frame to a bulkhead, in regard to it's use on a boat. It's very weak in comparison to bronze and can't tolerate the marine environment very long before "dezincification" occurs, rendering it a useless powder in the fastener hole.

Marine grade stainless (316 or better yet 316L) are okay if you're in fresh water and have a trailer boat that will be stored ashore. In salt water or a berthed craft, below the LWL, it will rust just about as quickly as other hardened steels. Stainless needs the presence of air to remain stainless. If it's buried in wet wood or immersed, the surface can't develop protective oxides and it rusts. It requires "free oxygen" to form the oxide coating which protects it. In water the oxygen is "captured" and can't help out the stainless. Ditto if buried in wet wood.