1990s spectrum restoration and tiller conversion

[LukeSaatk]

I scored this 1990’s blue fin spectrum 19ft for under a grand. It is kinda roached interior wise , but the hull doesn’t have a dent on it. I’ll keep posting pictures sporadically as I’m working on it. Any recommendations or tips are greatly appreciated. I’m just gonna write stuff out as I’m thinking about it.

1. The wood in the transom is rotted. The cap is welded, I assume I should cut the cap and replace the wood the weld it back on.

2. The foam they originally poured clogged any and all drainage routes which is why I suspect all of the old foam is waterlogged. I’ve heard using foam sheets is a better alternative to pouring foam.

3. I’ve traded a welder a KLX110 in exchange for work. We are adding a few more stringers because the top of the gunwales seem flimsy and no stringers run up the gunwales. He suggested that we add a knee brace or two for the transom as well.

4. Should I paint or seal the entire inside of the hull while it’s stripped?

 

[alldodge]

Welcome
It's got some nice lines, and most likely the stringers are also rotted

 

[DeepCMark58A]

Welcome
It's got some nice lines, and most likely the stringers are also rotted

It is an aluminum boat.

 

[alldodge]

It is an aluminum boat.

woopsie

 

[MikeSchinlaub]

Post a closer pic of the top and sides of the transom. All I can see is the splashwell wall. Usually you cut the cap and raise the sides up, but it's been a while since I've done one, and I mostly remember lunds.

Extra bracing surely couldn't hurt. Maybe add some around the seats too, so you don't end up making over sized holes when drilling blindly through the new floor.

I don't see any reason to paint the inner hull. It would just be a lot of work and money for something you don't even see. The aluminum shouldn't corrode anyway.

Don't used construction grade treated lumber for anything. The chemicals corrode the aluminum.

How well do you know the welder? Another member recently had a bad experience where a guy welded on some floatation pods and welded in way too long intervals. It severely warped the transom. Maybe ask for some test pieces of the same thickness first.

Oh, and do try to have fun

 

[LukeSaatk]

Post a closer pic of the top and sides of the transom. All I can see is the splashwell wall. Usually you cut the cap and raise the sides up, but it's been a while since I've done one, and I mostly remember lunds.

Extra bracing surely couldn't hurt. Maybe add some around the seats too, so you don't end up making over sized holes when drilling blindly through the new floor.

I don't see any reason to paint the inner hull. It would just be a lot of work and money for something you don't even see. The aluminum shouldn't corrode anyway.

Don't used construction grade treated lumber for anything. The chemicals corrode the aluminum.

How well do you know the welder? Another member recently had a bad experience where a guy welded on some floatation pods and welded in way too long intervals. It severely warped the transom. Maybe ask for some test pieces of the same thickness first.

Oh, and do try to have fun

Hopefully the pics look decent. Leaving the hull bare definitely would be easier, I’ll for sure fill it with some water and test for leaks. I for some reason don’t trust the rivets that are through-hull...

I’ve been told marine plywood isn’t treated and is the best to glue nautolex onto, I would get some coosa board but dang is it spendy.

Luckily I’ve know the welder for 15+ years and he specializes in aluminum.

I was going to do pour in foam but, somebody told me it’s better to do foam sheets such as polystyrene.

 

[LukeSaatk]

I also

Hopefully the pics look decent. Leaving the hull bare definitely would be easier, I’ll for sure fill it with some water and test for leaks. I for some reason don’t trust the rivets that are through-hull...

I’ve been told marine plywood isn’t treated and is the best to glue nautolex onto, I would get some coosa board but dang is it spendy.

Luckily I’ve know the welder for 15+ years and he specializes in aluminum.

I was going to do pour in foam but, somebody told me it’s better to do foam sheets such as polystyrene.

I’m thinking I may move the splash box back 12” to accommodate the tiler handle. Oddly enough the rear gunwale is just glued in.

 

[alldodge]

Mike might know better, but any BCX (note the X) plywood uses exterior glue. Many including myself have used BCX over marine plywood. The extra expense of marine ply is not worth it

 

[MikeSchinlaub]

Ok, I can't recall doing one quite like that, but you'll almost definitely be cutting the cap off to pull the transom out. I don't know what to do if it extends out to the tall sides.

@alldodge I really don't know much about the grades of plywood. Mostly just random bits. Like I don't know exactly what is different with the marine grades. I'm pretty sure they use different glues, but the stuff we get also doesn't seem to have so many air voids like construction ply does. I don't know if that because it's marine, or if it's a higher grade withing the marine catagory.

Also, now I know there is a marine version of treated. It's a pretty dark brown, and doesn't react with aluminum.

The stuff we get isn't even stamped, so I don't even have anything to read on the sheets.

 

[alldodge]

Cheap Exterior grade CDX uses the same glue as BCX and ACX. The A and B references the top surface layer, and the second letter (C vs D) is the amount of voids on internal layers. Marine uses same glue but guarantees no voids, hence why it's so expensive.

That said, most all the transoms I've done and read through threads have mostly been fiberglass covered, so there is less chance of water intrusion. Take it with a grain of salt

 

[LukeSaatk]

Mike might know better, but any BCX (note the X) plywood uses exterior glue. Many including myself have used BCX over marine plywood. The extra expense of marine ply is not worth it

I can get 3/4” marine plywood for $135 per sheet and 3/4” BCX for $44 a sheet. For less than half the price it seems worth it for the flooring. I’ll seal it with some MAS 2:1 Marine Epoxy then scuff it so the nautolex glue sticks.

Back to the transom, I’ve been told the steps are to epoxy the wood, strip and clean the aluminum skins, prime then use some 5200 adhesive to bond the two… I am getting excited for the welding to start in a couple days so I can start assembling instead of deconstructing.

Would it be a good idea to have square brackets right under where the seat boxes will be so I don’t have to guess where to drill?

 

[roscoe]

Use the best plywood you can get.
Glue and screw the 2 layers together to help keep it tight during the drying process. And clamp it the best you can. There are many waterproof wood glues to use, would not use 5200, but I guess you can. Mighty pricey though.

When all glued up, then seal the wood with OIL based Spar varnish, named "spar" for a reason. Or use Oldtimers formula sealer. These will soak into the wood filling all pores.
Not epoxy.

The best is Woodonglass's "oldtimers formula" 1 part boiled linseed oil, 1 part spar oil based varnish, 2 parts mineral spirits. let it soak in for a few coats, then cover with spar varnish.



Don't apply any nautolex or any other floor covering to the transom. It will only serve to trap any water inside.

I had one of these boats, for 8 years, 16'9" version. They were Brunswich aluminum version of a Bayliner, and their first venture into welded hulls. Yes made little on the cheap side, some corners were cut, but still a fairly decent boat.

Don't know what you plan on using for a motor, but shortening up the splash well is gonna help. Kind of a big project / modification, but if your welder is any good, he could fab up something decent. Otherwise any thing less than a "Big Tiller" version of a Merc motor is gonna be difficult to operate.
Gonna suggest 80 hp or more. 90 or 115 would be great.
The 1996 19' was rated for up to 115hp.

And add a 1/2" wooden transom to the outside, to protect that outside skin from being destroyed.

Pouring Foam in's and out's

Pouring foam may be a crucial part of your restoration, as it is required by USCG for all vessels under 21', it may be structural in your boat or just give you piece of mind. Here is how to pour 2lb or 4lb 1 to 1 mix foam: Be prepared before hand with all the "mixing" containers you may need I...

forums.iboats.com

You will find A LOT of good info for restoring and rebuilding aluminum boats, in the Starcraft boat forum, Here:

Starcraft Boats

forums.iboats.com

Good luck, have fun with it, do it right and you'll have a boat for decades.

There is a ton of info here on boats from some really knowledgable guys.

 

[LukeSaatk]

Use the best plywood you can get.
Glue and screw the 2 layers together to help keep it tight during the drying process. And clamp it the best you can. There are many waterproof wood glues to use, would not use 5200, but I guess you can. Mighty pricey though.

When all glued up, then seal the wood with OIL based Spar varnish, named "spar" for a reason. Or use Oldtimers formula sealer. These will soak into the wood filling all pores.
Not epoxy.

The best is Woodonglass's "oldtimers formula" 1 part boiled linseed oil, 1 part spar oil based varnish, 2 parts mineral spirits. let it soak in for a few coats, then cover with spar varnish.



Don't apply any nautolex or any other floor covering to the transom. It will only serve to trap any water inside.

I had one of these boats, for 8 years, 16'9" version. They were Brunswich aluminum version of a Bayliner, and their first venture into welded hulls. Yes made little on the cheap side, some corners were cut, but still a fairly decent boat.

Don't know what you plan on using for a motor, but shortening up the splash well is gonna help. Kind of a big project / modification, but if your welder is any good, he could fab up something decent. Otherwise any thing less than a "Big Tiller" version of a Merc motor is gonna be difficult to operate.
Gonna suggest 80 hp or more. 90 or 115 would be great.
The 1996 19' was rated for up to 115hp.

And add a 1/2" wooden transom to the outside, to protect that outside skin from being destroyed.

Pouring Foam in's and out's

Pouring foam may be a crucial part of your restoration, as it is required by USCG for all vessels under 21', it may be structural in your boat or just give you piece of mind. Here is how to pour 2lb or 4lb 1 to 1 mix foam: Be prepared before hand with all the "mixing" containers you may need I...

forums.iboats.com

You will find A LOT of good info for restoring and rebuilding aluminum boats, in the Starcraft boat forum, Here:

Starcraft Boats

forums.iboats.com

Good luck, have fun with it, do it right and you'll have a boat for decades.

There is a ton of info here on boats from some really knowledgable guys.

Thank you, nautolex was for the flooring not the transom, that would be a headache. I’ll look into the products you mentioned. I was thinking a 150 tiller after all the reinforcement. We are going to go pretty hard in the paint with all the stringers we plan on adding. Thank you also for the links. I’ll keep posting pictures as I go!