Shoestring Starcraft SS160 Resto-mod - let the long slow road begin

[ShoestringMariner]

I think too many people get caught up in the perfect paint job. Old boats are meant to spread joy with family and friends and the quest for ultimate shine can delay that.
If a boat is safe and water tight it should be making memories.

Yeah she’s not going to be that. She’s a 50’er. Dock rash on both sides. 2 rock strikes underneath. But I want the hull faired and painted. The sides can look 46-47 years old for another season….but someday she’ll be sharp. Function 1st, shine later

 

[ShoestringMariner]

Ok, so my Marine Tex just arrived. I guess I will have to mix small batches with dollar store measuring spoons. The admiral will kill me if I use hers

 

[renns]

For the G-Flex, I mixed small batches in empty single-serve yoghurt cups using a small digital kitchen scale to get the ratio correct. That worked out really slick - put empty cup on scale, and zero display, squirt in 'x' grams of part A, then 'x' more grams of part B, and mix. G-Flex is well-suited to that approach as it's dispensed in squeeze bottles, and is a 1:1 ratio.
I've got a Coat-it kit waiting for warm shop prior to application, and it's in cans of similar sizes to that Marine Tex. Dealing with alternate ratios is easy with the scale, but how does one dispense small volumes neatly without waste? Maybe some 'been there, done that' folks can chime in!

 

[SHSU]

Ok, so my Marine Tex just arrived. I guess I will have to mix small batches with dollar store measuring spoons. The admiral will kill me if I use hers

If you can, suggest using medical syringe. Makes it a lot easier to control measuring then a measuring spoon. Also, works well use as an applicator on the seem edges.

SHSU

 

[ShoestringMariner]

For the G-Flex, I mixed small batches in empty single-serve yoghurt cups using a small digital kitchen scale to get the ratio correct. That worked out really slick - put empty cup on scale, and zero display, squirt in 'x' grams of part A, then 'x' more grams of part B, and mix. G-Flex is well-suited to that approach as it's dispensed in squeeze bottles, and is a 1:1 ratio.
I've got a Coat-it kit waiting for warm shop prior to application, and it's in cans of similar sizes to that Marine Tex. Dealing with alternate ratios is easy with the scale, but how does one dispense small volumes neatly without waste? Maybe some 'been there, done that' folks can chime in

The scale is a great idea, thanks for that. I was using clear mixing cups for the Gluvit, but it was a pourable viscosity. I can just use mixing sticks to put dollops of marine Tex on the scale. It’s thick iirc.

 

[ShoestringMariner]

I was so torn on stripping vs sanding. Even after making the decision back to sanding, I decided it would give me a better understanding on how deep the pitting was and what pitting truly needed attention if I stripped it. This was first attempt at chemical stripping and I was surprised to see that there is deep etching where there was scratches or exposed aluminum. It should be easier to fill with the distraction of paint and bare spots gone.
What a job though! I will not be stripping paint on the sides when I get to that part. The paint on the sides save for a bit on the chines is in very good shape,

 

[ShoestringMariner]

Another crack at it got the starboard bottom stripped. I learned that the paint that sat submerged in the water was much, much easier to strip with the stripper. (One coat vs 3-4) The paint on the bow transition was stuck on like cat poop on a blanket and the aluminum beneath was pristine. I’ve also decided that stripping the keel and strakes are a waste of time. I’m going to sand them only. I’m not concerned about pitting on these and I also think that g flex on the rivet heads are a waste of time and material as I’ve stated before. I am only going to put g flex along the seam and rivets in the submerged zone also. A little more clean up on the keel, strakes and seam (chine) and I will start the other side. (Small shop, can only do one side at a time)

I hope to make much better time on the other side after what I’ve learned so far.

 

[ShoestringMariner]

Getting close to done stripping the other half. Would 100 grit sandpaper be coarse enough to prep the bare aluminum? I’m using it now for rough sanding (RO orbital sander) and the swirls don’t “look” very aggressive for a tooth.

I’m using interlux’s Interprotect 2000E 2 part primer and I don’t want to have an adhesion fail.

Thanks in advance

 

[renns]

Watching with interest! Are you using a self-etching primer below the Interprotect, or is it intended to go directly on bare aluminum?

 

[renns]

Watching with interest! Are you using a self-etching primer below the Interprotect, or is it intended to go directly on bare aluminum?

I did a quick run with the Google, and found the following link that might be of interest: http://www.marinetteboat.com/forum/viewtopic.php?p=1553&sid=720c70d619dbdf3844f54e6e7640e146#p1553

 

[classiccat]

Watching with interest! Are you using a self-etching primer below the Interprotect, or is it intended to go directly on bare aluminum?

I called interlux and they insisted that interprotect be applied on freshly sanded aluminum...the sooner the better for reasons highlighted in the link (oxidation). Mine is holding up great...zero signs of adhesion failure anywhere.

 

[ShoestringMariner]

Thanks @renns and @classiccat , I’ll have to sand it again before priming. The 2 marine supply places I deal with aren’t open again until Thursday and I don’t have the primer
So I’m the meantime, I’ll start the Marine Tex repairs (pitting, deep scratches) and the G Flex treatment. Then I’ll do a final sand over and prime. Hopefully I can get all that done and a few coats of the topcoat and let it cure a few weeks before I put it back on the trailer.

And maybe a good time to address a few hokey things on the trailer while it cures

 

[renns]

I called interlux and they insisted that interprotect be applied on freshly sanded aluminum...the sooner the better for reasons highlighted in the link (oxidation). Mine is holding up great...zero signs of adhesion failure anywhere.

That link describes using blasting media rather than sanding. That method would get the entire surface pretty evenly. When you're using orbital sander, is a hand-sand around (and on) each rivet head required?

 

[ShoestringMariner]

That link describes using blasting media rather than sanding. That method would get the entire surface pretty evenly. When you're using orbital sander, is a hand-sand around (and on) each rivet head required?

Yes, I’m in a bit of a sticky spot. In order to use the g flex, I’m supposed to (according to the video) strip the rivet head and immediate area to bare aluminum with a stainless wire wheel. So I have 2 processes requiring bare metal application.

3 if the marine tex needs the same bare substrate. If I can apply it on top of the Interprotect primer without gunking up the sandpaper when I have to level sand it, I may do that instead. I will check to see if I can do g flex on top of Interprotect which will really, really make my life easier. If I cannot, I will have no choice but to do tedious, careful sanding.
And if it is the latter, I may sand/prime one side at a time.

 

[classiccat]

That link describes using blasting media rather than sanding. That method would get the entire surface pretty evenly. When you're using orbital sander, is a hand-sand around (and on) each rivet head required?

abrading by hand around the rivets would work.

You'll want to Gflex before priming.

 

[ShoestringMariner]

abrading by hand around the rivets would work.

You'll want to Gflex before priming.

That’s what I thought, thanks CC

 

[ShoestringMariner]

@classiccat I have to ask about something you mentioned on another thread; “I've never worked with coal tar epoxy however I'm in the camp of coating aluminum with anything below the waterline (interior or exterior) is a recipe for corrosion in the long term. if you don't have perfect adhesion, it eventually delaminates and will trap water against the hull.”

Are you referring to rubberized coatings etc? You mention that you’ve used Interprotect with good results….was this below the waterline? It’s an epoxy I think. Wondering if I’ll have corrosion issues if I have any delamination. or would I just have peeling issues?

 

[classiccat]

@classiccat I have to ask about something you mentioned on another thread; “I've never worked with coal tar epoxy however I'm in the camp of coating aluminum with anything below the waterline (interior or exterior) is a recipe for corrosion in the long term. if you don't have perfect adhesion, it eventually delaminates and will trap water against the hull.”

Are you referring to rubberized coatings etc? You mention that you’ve used Interprotect with good results….was this below the waterline? It’s an epoxy I think. Wondering if I’ll have corrosion issues if I have any delamination. or would I just have peeling issues?

The only area that I painted (Interlux system) on my SS18 below the waterline is on the transom and it's a trailer queen; the majority of my exterior hull is bare down there . So far all of my paint looks like the day I applied it. I'm not sure what a failing interlux system looks like; everywhere that I put it down is holding strong.

Interprotect is marine product and if you follow the surface prep & application instructions you'll be be fine. The interlux primers seem to be relatively flexible however if it's top-coated with a hard 2-part (like perfection) an impact that flexes the hull skin would probably make it crack and peel off since it's so rigid...whether or not it would take the flexible interprotect / primekote with it I believe depends on whether or not the surface was prepped properly.

 

[ShoestringMariner]

I’ve been thinking about the subject of corrosion due to trapped moisture, and the next processes I’m getting into is the floatation foam. The original waterlogged foam was laid on top of the ribs and not the skin of the hull IIRC.

Because I want to add a rod locker in the floor, I want to add maximum rigid styrofoam under the floor and as many places as possible. I’ve seen some lay foam between ribs against the hull skin itself. This gains another inch of thickness area, but I’m now worried that this could trap moisture and cause corrosion.
I was also planning on building the foam right up to the plywood to maximize the foam content but also to add floor support. With OTF treatment and several coats of spar protect the underside enough? Or is epoxy my best bet there also?
TIA

 

[renns]

I can't see there being an issue between hull and foam, as it's on a slope and the foam is sitting loose on the bottom, not adhered to it like old spray/pour-in stuff.
Now up under the decking, perhaps that might be a potential issue? I suppose it'll depend how precisely fit the pieces are, and if you have them laying flat or on edge.
I've gotta admit having you one step ahead of me on a very similar project is quite helpful! I'll sit back now and wait to read the thoughts of those more experienced members to follow!