1986 Blue Fin restore

[bscappell]

Re: 1986 Blue Fin restore

It's all about molecular bonding and curing. If you don't recoat within the short time frame you need to wait for a full cure before the next coat. If you used hardener in the paint, I'd wait a week before putting her back on the trailer. If you did not use hardener I'd wait 2-3 weeks.

thanks for the explanation. i used hardener and i will wait till next week to flip over.

 

[bscappell]

Re: 1986 Blue Fin restore

So i need to do a repair on bottom of the boat at the stern. It appears that a PO did god only know to the stern area. A friend welded the knee brace (he must know what he is doing because he didn't blow through that thin stuff) that is inside the hull above this and so I'm not so much worried about the strength as i am about a leak or a remote possibility of hitting something there again. i was going to treat it like this article does: WEST SYSTEM | Metal Boat Repair - Patch holes in aluminum boats with G/flex Epoxy

then place an aluminum plate over it to prevent further abuse. then i got to thinking that a plate might screw with the hydro dynamics of the boat. should i just scrap the plate all together?

here is the area in question:



the plate idea:

 

[jasoutside]

Re: 1986 Blue Fin restore

I like the plate idea. Notch trowled with 5200 and riveted in place would be solid!

 

[bscappell]

Re: 1986 Blue Fin restore

I like the plate idea. Notch trowled with 5200 and riveted in place would be solid!

thats what i was thinking but i am concerned about the hydrodynamics. what do you think?

 

[jasoutside]

Re: 1986 Blue Fin restore

Nah, I wouldn't sweat it. We have riveted boats, all that is ruined anyhow.

 

[bscappell]

Re: 1986 Blue Fin restore

West System if you are rich n famous.

US Composites if you are just famous.

thanks Jas

looks like 635 resin in the gallon with 1.5 quarts medium hardener should be enough? or can i get away with the 1/2 gallon kit? my transom is 2' at the widest and 6' at the longest. of course there is less than 12 square feet to cover. probably more like 9 square feet. so 5 coats (1 for sandwich 4 for 2 sealer coats) at 9 square feet is 45 square feet needed to cover. is that right? no glass for a tin boat correct?

looks like, according to their site, the 1/2 gallon (which is more than half gallon when mixed) would be enough, and have left overs for sure (165 square feet of coverage):

30. What is the coverage of your epoxy when sealing plywood?

There will be slight variations depending on how heavy it is applied. Generally speaking, a gallon of epoxy will yield 250 square feet. Therefore a typical 4'x8' sheet of plywood would require about one quart(32oz) to seal both sides.

anything else for the good of the order with the transom?

 

[Woodonglass]

Re: 1986 Blue Fin restore

1/2 Gallon is Plenty I like having the Pumps for measuring but you don't have to have them.

 

[bscappell]

Re: 1986 Blue Fin restore

1/2 Gallon is Plenty I like having the Pumps for measuring but you don't have to have them.

Agreed pumps seem like an easy thing for 6.75

 

[jigngrub]

Re: 1986 Blue Fin restore

I strongly suggest getting enough epoxy resin to seal all of your decking too, the gallon kit should be enough to do your transom and decking.

 

[bscappell]

Re: 1986 Blue Fin restore

I strongly suggest getting enough epoxy resin to seal all of your decking too, the gallon kit should be enough to do your transom and decking.

and the benefit of this over spar urethane?

 

[jigngrub]

Re: 1986 Blue Fin restore

and the benefit of this over spar urethane?

Much much stronger and about the same price.

I've used spar for sealing some small things on the boat when I run out of epoxy, and the more I use the more dissatisfied I become with it. So dissatisified I won't use it anymore, I'll just order more epoxy. Spar is weak.

If you're going to spar the deck, spar the transom too. If you're going to epoxy the transom, epoxy the deck too... epoxy will be your best build.

 

[Woodonglass]

Re: 1986 Blue Fin restore

Not trying to be argumentative but according to my pricing, a 1/2 gallon kit of Epoxy from USC is $42 bucks + shipping which depending on where you are will be appox. another $20 bucks. this will yield a bit over 3/4 of a gallon of Epoxy.
A Gallon of Spar Varnish, on Average at the Big Box Stores is $35-$40 bucks. Quantity for quantity that's about double the cost.

If you're looking for added strength then the epoxy will indeed give you that and some added durability. It does not have UV so it does require some sort of covering, either paint or carpet or Spar Varnish. If all you are seeking is to seal the wood and some added durability spar varnish will give you this. It's used on wood boat decks and wood floors all the time and holds up fairly well.

 

[bscappell]

Re: 1986 Blue Fin restore

Much much stronger and about the same price.

I've used spar for sealing some small things on the boat when I run out of epoxy, and the more I use the more dissatisfied I become with it. So dissatisified I won't use it anymore, I'll just order more epoxy. Spar is weak.

If you're going to spar the deck, spar the transom too. If you're going to epoxy the transom, epoxy the deck too... epoxy will be your best build.

so then i would still need something to bond the two pieces of plywood together. Any ideas? i was going to just use spar throughout but I know that it is not looked kindly upon in these parts.

Woodonglass brings up the other point i was thinking too. it is cheaper. maybe not as effective but cheaper. still i need a bonding agent.

does it not make sense to use the same glue the plywood manufacture uses to make bond their plys? is there not retail version or
is the process they use in the factory not repeatable in the hobby shop?

this isnt my forever boat. plan to sell in 4 years or so and move to another project or spring for a welded boat.

 

[Woodonglass]

Re: 1986 Blue Fin restore

If you're talking about gluing the two pieces of plywood together to make your transom, I'd use Titebond III wood glue. Easy to work with and yields a highly water resistant bond that will never give you any delamination issues once the transom is sealed and installed properly. If you are on a budget sealing the wood with the varnish and then 3-4 coats of oil paint will give you a transom that with proper care and maintenance will last you for 10+ years. Of course, that's just my opinion but it is based on lots of research and experience.

 

[bscappell]

Re: 1986 Blue Fin restore

If you're talking about gluing the two pieces of plywood together to make your transom, I'd use Titebond III wood glue. Easy to work with and yields a highly water resistant bond that will never give you any delamination issues once the transom is sealed and installed properly. If you are on a budget sealing the wood with the varnish and then 3-4 coats of oil paint will give you a transom that with proper care and maintenance will last you for 10+ years. Of course, that's just my opinion but it is based on lots of research and experience.

that is what i am talking about. this was my original plan and yes i am on a budget so this is maybe my best bet. the oil based paint is just another layer of protection? my transom is not exposed to UV at all.

 

[jigngrub]

Re: 1986 Blue Fin restore

Truthfully, anything is better than the nothing that the manufacturer used to seal the wood in your boat... You could skip the spar and just go with an oil based paint if you want, or even a good exterior grade latex porch and deck paint.

 

[bscappell]

Re: 1986 Blue Fin restore

Truthfully, anything is better than the nothing that the manufacturer used to seal the wood in your boat... You could skip the spar and just go with an oil based paint if you want, or even a good exterior grade latex porch and deck paint.

this is true. any idea what they used in the factory to glue the plywood transom pieces together?

 

[jigngrub]

Re: 1986 Blue Fin restore

this is true. any idea what they used in the factory to glue the plywood transom pieces together?

More than likely it was resorcinol glue/adhesive, the same thing the glue the carpet down with. 100% waterproof contact cement type adhesive.

Resorcinol is hard to find at the retail consumer level, I've looked for it but can't seem to find a current supplier. I found where Dap/Weldwood used to make and sell it, but again no current supplier.

The Tightbond 3 that Wood mentioned will do a good job, as well as the PL premium and Gorilla glue. Making your own with epoxy resin and a powder filler designed for it would be the strongest build IMO... but since you don't plan to keep your boat the other 3 choices will do well for what you need.

 

[bscappell]

Re: 1986 Blue Fin restore

update:

last week i picked this jig saw up at a pawn shop with blades for $40. thought it was a good deal:



so i cut this:



and this:



the transom in ACX 3/4". 7 ply's per piece for a total of 14 plys. glued with titebond3. old transom was only 10 plys so this ought to be strong.

the aluminum piece sits between the transom and splashwell. old one was cracked and corroded.


boat will be flipped over tomorrow. but i got westsystem g/flex in mail to patch some things. yeah i know, after paint job? stupid but i just didn't feel comfortable leaving it as is. plus these two spots will have an aluminum plate over it. Diamond plate scrapes for a local metal shop. $2 a pound and i feel like i got good deals on the sheet.

prepped:



After:





ran out of picture room---------------->

 

[bscappell]

Re: 1986 Blue Fin restore

and recovering the bunks:



rest of the week:

dry fit and drill the transom
have buddy finish welding the knee brace
seal transom
finish cleaning the interior rivets in prep for "coat it"
maybe some carpet install degrease the motor if time alllows