1984 starcraft islander

Sharpie223

Petty Officer 2nd Class
Joined
May 24, 2021
Messages
166
I wouldn't expect the solvents to melt the foam, but if its polyurethane foam, xylene should degrade it, possibly allowing it to release easier. This is assuming that you are removing all foam, I'll admit I haven't read closely enough to see if that was the case here or not. Either way, make sure it's all gone prior to using the boat.
 

Neschenbrenner

Petty Officer 3rd Class
Joined
May 10, 2020
Messages
76
I'd recommend a nylon cup brush, the bristles are easier to work in than wire, and don't shed like wire. For something relatively soft like foam, the wider bristles should make quicker work as well.

A pressure washer might work as well. Possibly pretreat with xylene or acetone.
I've been using a nylon brush works great.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,827
Using strong solvents may not be a good idea.----If you have sparks for any reason it might go " woosh " around you.
 

Neschenbrenner

Petty Officer 3rd Class
Joined
May 10, 2020
Messages
76
Idk if you can see it in the picture but theres just a little foam I can't get around the ribs and stuff like that.
 

havoc_squad

Senior Chief Petty Officer
Joined
Mar 5, 2011
Messages
738
What's the best way to find leaky rivets? Also should I pull the gas tank out.
You're this far into it already, do you want re-work later to have to pull it out if it leaks after putting the floor down?

Yes, you do want to pull the gas tank for inspection. If there are no critical corrosion issues or cracks in the inspection, cap the ends and pressure test it 2 to 5 PSI max I believe (Low pressure, it's not an air compressor tank) to make sure it doesn't leak.
 

Neschenbrenner

Petty Officer 3rd Class
Joined
May 10, 2020
Messages
76
So how worried should I be about these pits there's not a ton but there are few here and there.20230402_181526.jpg
 

Sharpie223

Petty Officer 2nd Class
Joined
May 24, 2021
Messages
166
Where are the pits located? That will determine what level of remediation is needed.

Also how deep?
 

Sharpie223

Petty Officer 2nd Class
Joined
May 24, 2021
Messages
166
Hard to say.

No matter what I would use the nylon brush to clean out the pits, maybe acid clean, and then fill with a fortified epoxy.

If the pits are over a keel strip, I wouldn't worry any further. If they are deep or in a seemingly high stress location, I'd look into patching. Deep and high stress become subjective unless you really want to dive into calcs and modeling.
 

Neschenbrenner

Petty Officer 3rd Class
Joined
May 10, 2020
Messages
76
I
Hard to say.

No matter what I would use the nylon brush to clean out the pits, maybe acid clean, and then fill with a fortified epoxy.

If the pits are over a keel strip, I wouldn't worry any further. If they are deep or in a seemingly high stress location, I'd look into patching. Deep and high stress become subjective unless you really want to dive into calcs and modeling.
Is there a specific epoxy you would recommend?
 

Sharpie223

Petty Officer 2nd Class
Joined
May 24, 2021
Messages
166
Honestly, I should modify my previous comment. My main concern with a pit is if it's large enough to cause the base metal to be weak. Since there are holes all through the boat, if it's not at a riveted joint or an obvious high stress path, it probably won't be a concern.
The second issue is corrosion likes crevices, so it creates a spot for further corrosion. This is where I would want to seal it or treat it. Epoxy will seal it, but even flex coatings could possibly peel, allowing moisture to be trapped underneath.
A chemical coating may possibly be better if it passivates the aluminum itself. I think alodine is commonly used for that, but I have zero experience. Zinc chromate primer is used as it will preferentially corrode rather than the aluminum underneath. I don't know how either perform in existing pits.

In my boat, the pits I filled were all the way through, and at the knee brace rivets. I decided to fill with jb weld and patch on both sides. That was just to help seal, the 5200 on the patches does most of the job however. I don't know that I would trust jb weld on its own.

Take my ramblings as things to think about rather than clear paths forward.
 

Moserkr

Chief Officer + Starmada Splash Of The Year 2021
Joined
Nov 23, 2020
Messages
869
Heres what I used - a two part epoxy type paste and I smeared it all over my transom which had lots of pitting, some almost all the way through. Nothing to worry about as the structure still remained and after nylon brushing the transom, plus cleaning with a vinegar water solution to neutralize the corrosion, it should be all set for the next 40 years. Believe it was recommended to me by others on the forum during my resto.

D242211C-50AE-4C22-8FE5-4D16FF6507D8.jpeg
 

Sharpie223

Petty Officer 2nd Class
Joined
May 24, 2021
Messages
166
I've been using pc7 as filler in places, which is glass reinforced, as well as some other unknown fillers. It's tough stuff, doesn't shatter when hit with a hammer and hard to clean off the mixing tools. Pc11 I think is supposed to be the "marine" version, maybe more flexible, or made to be applied underwater or something like that.
 

Neschenbrenner

Petty Officer 3rd Class
Joined
May 10, 2020
Messages
76
Finally got around to doing a compression test on the engines. I don't think it looks good but I'm not an engine expert.

Left
1= 100
3=75
2=110
4=90

Right
1=75
3=90
2=80
4=80
 
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