Restoring an old aluminum

[erikrs301]

I'm looking at project hulls, 18'+ 70's-80's Starcraft, Sea Nymph and some other aluminum center consoles. I want to gut it to the bare hull, strip & refinish it properly, then lay it out the way I want.

Is there anything I should be looking out for that might be a royal pain in the ass the repair or somepletely unrepairable? I'm expecting to entirely replace floors, console and transom.

[done workin]

Fill it with water Just enough to cover the bare hull) and look for leaks in the seams. Everything else is already being replaced.

You just don't want to replace everything and then have the hull leaking.

[POLECAT]

Chances are you will have leaky rivets. I have completely redone several 1970's Starcraft hulls and they all had rivets that were loose, missing, or needed to be replaced due to corrosion.

Most 70's hulls need a reinforcing bracket at the ends of most ribs. Not an easy job if done correctly. The brackets are made using 8" X 8" plates bent at various angles to conform to the changing deadrise of the hull. To install the brackets for only one rib requires complete removal of the rib (88 rivets) and reforming both ends of the rib (also not an easy job). If you're not willing to do this to at least 11 ribs, don't even begin this phase of the rebuild. This is the most extreme part of the rebuild if you want to end up with a rock solid hull that is better than when it left the assembly line. (Starcraft changed their design to eliminate this problem in the mid 1980's.) Like I said, this is extreme. Most people do not do this. You could buy a new boat for less than what the labor alone would cost.

Check questionable rivets by tapping the heads sideways with a hammer and cold chisel. A slight tap on the edge of the rivet will reveal if it is solid or needs replacing. Don't be too surprised if you see the heads fly off easily. If 5 out of 25 prove defective, you have a major reriveting project on hand! Only way to end up with a decent outcome is to use rivets exactly like what the boat was assembled with (solid marine grade rivets) enlisting the aid of a friend to buck the rivets while you use a pneumatic rivet gun (not an air hammer). Sounds like lots of fun up to this point, doesn't it?

The first rivets to fail on Starcrafts are the ones at the chines. They are 5/32" diameter, closely spaced, connecting the bottom to the sides. They are in and out of the water more than any of the other rivets on the hull and the (salt) water and air both get a greater opportunity to reak havoc on their chemestry. They are the first to decompose, in part due to their small diameter.

Unless you are willing to do some serious rivet replacement on a 30 year old hull, don't waste your $$$$.cc on the deck, transom, console and other parts of the rebuild. You will end up with a leaker for absolutely certain...... and you will not be a happy boater.

Good luck!

[erikrs301]

Thanks for the info! I think we're going to shy away from the 70's hulls and at least try to get something from the 80's if not early 90's. I found an '85 19' Bluefin dual console and an '86 19' Sea Nymph CC. Both have a foot wider beam then the Starcrafts and are 10-12 yrs newer.

[C-Hawk18]

Just as an FYI ...the BlueFin was made by Brunswick. Kinda on the same quality level as Bayliner.
I personally would lean more towards the sea Nymph.

[erikrs301]

Yea, we're leaning towards the Sea Nymph because it is already a center console layout. I noticed Bluefin became Spectrum and I was never impressed with their product.

[Bay Bob]

I rebuilt a 50 year old Jon-boat that had extensive corrosion issues. It is a bit of work but not expensive if you do it yourself.

Couple things to consider.

You need to revove all corrosion and this means a total disassemble, seperating all joints.

You can power wire brush and use a chemical cleaner.

Every rivet hole should be redrilled slighty larger and a larger rivet or fastener installed.

Once you get it clean and re drilled you should use a product called Alodine to help prevent new corrosion. It creates an oxidized surface similar to anodizing.

Every rivet and seam should be sealed with poly-sulfide or other good durable sealant.

I have done this project with stainless steel screws and SS selflocking nuts, perhaps putting an SS washer on the inside.

Do it right and it will last another 50 years !

BB

[Bay Bob]

These fasteners are "the berries". They have a hex hole on the nut side and can be easily installed from one side.

Little hard to find, but worth the effort.



Happy metal bending !

BB

[Matt]

I've had good luck reworking the rivets with one guy holding a hammer head tight on one side of the rivet and another giving the rivet a solid tap from the other side. My old alum leaked a gallon per hour before we did this, then it barely leaked. We did need to patch a few pinholes with pc7. Ten years later I gave the outside of the hull a good wire brushing and painted it with some leftover epoxy paint. Its been leakfree ever since.

[erikrs301]

Well, I still don't have a project hull sitting in the yard. Keep the info coming, I'm still looking!

I did find a 16' Grumman CC that had a 7' beam but it was pretty rough. Might go check out a 1981 18' Starcraft CC this weekend.