How To Repair Scraped Aluminum Boat Bottom

• #1

I was given a 15' Starcraft today, the boat is pretty much gutted, the transom and flooring are all out and it'south been stripped for repaint.
My concern is patching a fairly deep scratch or gouge along the right lower side virtually a pes below the water line. The last owner said he brushed past a submerged piling which had a commodities head sticking out of it. The gouge is about 5" long and it starts virtually 3" ahead of an internal rib, the metal is deeply scratched and slightly indented, and where the scratch met the area where the rib reinforced the outer skin it punctured through at that point and at the end of the scratch, in the middle of the rib. None of the punctures are visible from inside the gunkhole, even with lite behind it at dark. Water rushes in pretty fast. In that location is i rivet that's well-nigh 1/eight" from the puncture, merely it's not hit, but it's close enough that welding volition no doubt compromise the rivet. I've taken the boat to several welders in the expanse and none will bear upon information technology.

What would exist the proper set for this? Each puncture is less than 3/16" long. I'chiliad thinking about roughing up the surface area on the outside and filling in the damaged area with Marine Tex or JB weld? Will that hold and exist safe?
Volition JB weld adhere permanently to un-primed aluminum?

I already bought a quart of Gluvit for the inside of the hull simply Gluvit alone won't reach or fix a 'cutting' in the hull like this. I'm certain this is why the gunkhole was free, it no incertitude leaked water pretty bad. The last possessor had half a tube of silicone caulk spread over the repair, so he knew it was in that location. Information technology'southward also in an area that contacts the bunks when loading.

I'm thinking of filling in the exterior with JB weld and coating the inside liberally with Gluvit equally best I can?

• #2

Re: Deep scratch or gouge in aluminum hull below waterline

I call up pictures are in lodge hither. It is very hard to SEE what you are describing without them

Bob_VT

Moderator & Unofficial iBoats Historian

• #4

Re: Deep scratch or gouge in aluminum hull beneath waterline

Yes, the method you described will work. There is a product chosen PC11 (or if you use marine tex - use the gray stuff) which you can use externally then a few coats of gluvit internally should seal it up fine. Welding is the top pick but the adhesive road volition work.

Now if yous are real concerned about the strength y'all can as well rivet a support patch in the inside. That would be sealed and out of site also.

• #6

Re: Deep scratch or gouge in aluminum hull beneath waterline

Oh man, free Starcrafts are the all-time!!!

• #7

Re: Deep scratch or gouge in aluminum hull below waterline

I have used PC-11 and it is FANTASTIC stuff. Very much like MarineTex. Smooth and Sands very well. You tin can even drill and tap it.

• #viii

Re: Deep scratch or gouge in aluminum hull beneath waterline

I don't have any pics yet, I have to get the gunkhole up off the bunks to get a flick of the damaged area.
It looks like a deep scratch merely it's through at the one end, and that end happens to fall beneath an aluminum rib. The area is just about where the ribs end, the scratch is almost not visible at all unless your actually looking for information technology. I wouldn't have seen it if the guy didn't accept a load of silicone on it. The last guy to endeavour a repair smeared nearly a half pound of silicone over the area making it expect much larger than information technology really is. He claimed that the boat leaked near a gallon an hour, I'd say about triple that is more than like information technology but guessing past the hole. I found the hole only since I institute water dripping from the patch, information technology was raining really difficult on the ride abode and it got wet. The deck is removed, equally is the transom, but the damage tin can't exist seen from the inside at all, the scratch does make a bit of a dent just not enough to show through on the inside. I showed information technology to a few welders around here and all said that the leak was too shut to a rivet and that the rivet would have to be sacraficed and the rib in turn welded downwards. Information technology'southward non that bad of a scratch. The actual punture is no more than the size of a minor blast pigsty in 2 places, the scratch was front end to back, where the object passed over the hull effectually the rib, information technology punctured the aluminum slightly, and again where information technology stopped. I could probably do the same damage with an ice selection if I pushed difficult and dragged it well-nigh 4" against the hull by manus.

I don't take whatever doubt that epoxy will fix the leak, but volition information technology stick forever? Fifty-fifty if it barbarous out, the gunkhole would be in no real danger of sinking in whatever hurry. It would take hours, if not days to take on that much h2o. I haven't float tested it but I did fill it to embrace the ribs and water barely comes out that hole, you have to stone the boat around to make it leak at that place. Water needs to seep backside that particular rib to get out. Since there's a rib backside the damaged area, an inside patch won't piece of work, and its by far not serious enough to remove the rib to repair.
I idea near those Alumiweld sticks but I've seen mixed results with that stuff. If I knew information technology would adhere ameliorate than epoxy, then that would be the way to go simply I'm not that confident taking a torch to the hull with that stuff.

• #x

Re: Deep scratch or gouge in aluminum hull below waterline

Epoxy doesn't like sunlight but y'all could pigment it or cover it with filler and paint the repair.

Alumiweld works but its not really good for annihilation structural and if information technology'south close to a rivet, you will almost likely loosen that rivet with heat and aluminum does warp when welded. The platonic fix would be to be able to get to the rear of the hole, tap the pigsty closed over again, and seal the rear with either epoxy or even 5200 so fill and paint the outside. Chances are it will out last you barring any direct impact with that area. I've establish that calculation any double metal patches just creates a place for corrosion to begin if the gunkhole is used in saltwater. I've removed a few riveted patches from older boats where the aluminum corroded badly where salt got trapped behind the patch.
Virtually of the punctures I've dealt with on aluminum hulls were at or behind ribs. The panel area between the ribs but gives more and resists puncture. The aluminum is held tight by the rivets behind the hollow rib and that seems to exist where a precipitous object makes its style through.

As far equally how well epoxy sticks, I but spent two hours scraping and sanding off an epoxied on patch on a 14' boat. Someone had smeared JB weld or similar epoxy over several unused holes in the transom but the repair looked like it was done with a trough and the holes behind it were crude, ane had a rusted screw snapped off, and it wrapped effectually under the boat. The stuff sticks and stays stuck. Merely this wasn't actually in direct sunlight and they did brush paint over peak of it. It was too below the h2o line and didn't leak.

• #eleven

Re: Deep scratch or gouge in aluminum hull below waterline

Since this is below the waterline UV is non going to be much of an effect. Will information technology stick for ever? If yous prep the area well, i.e. wire bursh, wash downward with 50/fifty of white vinegar and water, dry Really Practiced, mix the PC-11 50/50 so Aye it volition terminal as long as you have the boat. If y'all are going to paint the bottom of the boat, so much the better. Just remember to prep information technology correctly, and apply a self carving primer before yous paint. Do all of this and your repair will be there as long as you have the gunkhole.

http://www.correct-tool.com/pcwhiteppas.html

Or Nearly Ace Hardwares Conduct PC-11

Remember PREP is the KEY to good Adhesion!!!!

• #12

Re: Deep scratch or gouge in aluminum hull below waterline

I took the bare hull downward to a pond today to leak test, I wanted to see what and where the leaks were earlier doing anything. The area of business really don't leak that bad, it produced simply a modest steady trickle of water. I got more water coming in around a fix of poorly sealed screw holes on the transom. There are 17 holes drilled at bottom of the transom where things were bolted on at in one case. I brought the boat dwelling house, dried it out, and figured that I'd try to see if I could brand the impairment any better before patching it. I drilled a i/4 inch hole in the stringer correct where the hole was, I then had a buddy concur a chunk of heavy metal where the scrape is, while I tapped the scratch out and airtight upwards the tiny hole with a long dial. The scratch is at present most flush, the hole doesn't let any calorie-free through. I then opened upwards the stop of the rib a bit with a bit and dripped in some Gluvit. I and so sanded the scratch area and wiped it with alcohol, so I mixed and spread some white Marine Tex over the area as if I was spreading body filler. Correct at present, while not yet fully cured, the scratch is near invisible since the epoxy blends in so well with the white painted hull. The bodily hole or puncture was less than the bore of pencil lead. I also tightened up the surrounding rivets. One time information technology cures completely I'll give it another dunk to check for leaks. I also sanded, dimpled, and filled the spiral holes the aforementioned way. Most of the spiral holes were just covered over with white tub sealer.

Which is meliorate, Marine Tex or PC-11? (PC-11 certain is cheaper).

• #13

Re: Deep scratch or gouge in aluminum hull below waterline

They are BAsically the same product. For the Price, I have always utilize PC-11 and gotten the same results

• #14

Re: Deep scratch or gouge in aluminum hull beneath waterline

Well, the fix looks skillful, but I guess I'll never know first hand if it leaks.
I had the boat sitting on a trailer that I had listed for sale, information technology was a bunk trailer so it left the damaged area exposed to piece of work on.
I had a guy stop past today in the rain to meet the trailer and afterwards he looked the boat over, he decided he wanted the boat and not the trailer. I sold the gunkhole and another bunk trailer I had here for $1200 cash. The trailer was an old painted bunk trailer from the early lx'southward, ane of those mono beam blazon trailers with rollers downwards the heart and a set up of rollers in the center on the sides. It was rusty and needed a lot of work, I was going to but flake it. This guy had to take it.
I basically gave him the trailer with the gunkhole. The boat was a bare hull, no wood, no steering, no nothing. I really wasn't planning on selling it but later he made me an offer of $1000, I had to stop and think, when he said $1200, he bought a gunkhole. I'll find another.
I had no idea that these things had such a following. And then much for that project, I guess it's on to another.

Source: https://forums.iboats.com/threads/deep-scratch-or-gouge-in-aluminum-hull-below-waterline.449004/

Posted by: doughtyvased1986.blogspot.com

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