Steel hull inside rust

[Jahoo]

Hiya all!

I just bought a cheap old (possibly homemade) 30ft steel hulled boat, wanting to jump right into the boating world and start seriously cruising in a couple years. I'm not sure if I should treat the current boat as a temporary, learn what to look for in a real boat or if I can deck her out for world sailing.

It is on hardstand at the moment and i've chipped out a lot of concrete from the bilge/keel area. I found a bit of rust under where the concrete was - if anyone has any opinions about the extent of the rust it would be fantastic! Not sure if I should feel safe in the water with a simple brush down and paint job/a steel plate needs to be welded to isolate the keel / the whole thing needs to be re-plated.

Also, I've found a weld line on the inside of her, not anywhere that water would puddle that had some rusting, is this an indication of a hairline crack to the outside of the hull?

I'm attaching some pictures - and unless she is a total write off, I'll be rebuilding her start to finish and will post more.

Thanks all!

[boatman61]

Hi there Jahoo...
Sorry... I'm absolutely no use whatsoever re-advice on steel boats...
But... Welcome to CF..

[atoll]

a compressed air needle gun,phospheric acid and epoxy tar are the way to go if you cannot grit blast.
be careful about attacking rust below the waterline if you are in the water,i have had friends punch holes through the hull accidently on badly rusted sections!

cutting out suspect sections and replacing plate is fairly straight forward with the right equipment if interiour furniture is removed but be careful about fire.

welcome to cf

[conachair]

Very good download here..

Metal Boat Repair and Maintenance: Your Ultimate Do-It-Yourself Guide by Scott Fratcher (eBook) - Lulu

Or a google preview here..

Metal boat maintenance-A do it yourself guide - Google Books

Hard to tell from a few pics, but looks salvageable, lot of dirty work though. What you really need is someone with a good ultrasound meter to find out how much steel there is.

Good luck!

[GordMay]

Greetings and welcome aboard the CF, Jahoo.

[DirtRdEarl]

Hi,

I agree with Atoll. Does not look too bad. Use a pneumatic needle gun and clean the area to a bright metal finish. I've been an industrial paint contractor for 40 years. Sherwin-Williams has a product (920 Pre-Prime), it goes on like water, and penetrates very well. Good for steel and concrete. 1 thin coat to seal everything. I would use 2 coats of epoxy for the finish. Coal Tar Epoxy is good also, just use 2 or more coats. The rust by the weld is an area that did not get enough paint the first time. Very common. Pay close attention to corners, edges and hard to reach/see areas, this is where inadequate paint will show first. Thid is not hard to do, just have adequate air supply. It would not bother me at all. Any one with a steel hull will have the same problems. Just routine maintenance.

Earl

[hpeer]

Two steel boats, ditto all the above.

Except the ultrasonic. Not that it is bad, I might even buy one myself. However, it is hard to take measurements sufficiently close together to assure you have covered the entire hull.

My first choice would be a ballpean hammer.

You must have got her for a song. I know of a similar situation here in Delaware. Old guy has a nice 30' Steelie his back yard, needs a mast and some work. No takers.

I've got two already, so I'm not going there.

[conachair]

Originally Posted by hpeer

Except the ultrasonic. Not that it is bad, I might even buy one myself. However, it is hard to take measurements sufficiently close together to assure you have covered the entire hull.

My first choice would be a ballpean hammer.

Agree.
Or even better, both.

Nice to know for sure.

[boden36]

After you have cleaned it up with a needlegun, if plate thickness is suspect, there is a quick fix called 'doubling'.
With the boat out of the water, lay a piece of 3mm plate over the suspect area on the outside.
Wedge or bolt the plate into place, and weld around it. If you have used bolts, take them out and weld up the holes.
So long as there are no holes in the original plate, there will be no rust between the plates as the air can not get in.
If there are any holes in the original plate, you will have to seal them with weld.
If it is a big plate, a few plug welds in the middle wouldn't hurt.


Regards,
Richard.

[Boracay]

Depending on how bad the rust is it may be attackable with a Dremel type tool and ball end diamond bits.

After an el cheapo tool failed on me I got a Ryobi "kit" and that's held up fairly well.

I haven't done it but rather than welding on the outside I'd weld a plate (or plates) on the inside.

Cow of a job, though.

[SabreKai]

She doesn't look half bad. I went through the same affair with an HO-28 years ago, chipped out all the cement and boiler punchings. She had had water standing for a long time and the joint between the lower chine and the keel can was down to half its normal thickness. Yours looks a lot better. As mentioned above, best is grit blast, if you can do it and the furniture is out. Rent the gear and have at it. Next best is the scaler, wear ear plugs under your hearing protection. Also as noted, really bad spots can be doubled or cut the offending piece out and put in new plate. Never hurts to learn welding if you own a Steelie and the skill will stand you in good stead. Again, the gear can be rented. I have some long patches of rust along the chine joints and am thinking about building up the area by welding inside in small patches. Certainly easier than cutting and fitting a 4 foot long by 2 inch wide strip.

That weld with the rust is where someone neglected to chip off the slag before painting. If you look closely you can see the slag spalling off the weld and the wider areas are where the paint film was damaged and then moisture penetrated in ever widening area. Hit the joint with the scaler and then repaint.

Looks like you got yourself a keeper.