removing tar from aluminum hull?

[reelfishin]

I picked up an older Jon boat the other day, it looks to be in nice shape, it's probably from the late 50's or early 60's. The last registration sticker is from 1966.
Someone has covered the entire bottom with what looks like either automotive undercoating or roofing tar. It's about 1/8" thick and dried out and crackled on the surface. They have it only on the bottom, but it's got runs all over.
I was thinking a can of gas, a few old rags and a wood or plastic scraper, but that could take a while.
Any ideas on removing this mess?

It's one of those textured Sears hulls, the kind that looks like an old lunch box or cooler. Sort of a wrinkle or hammered finish. It don't leak, but it looks pretty nasty with all that mess on it, it also gets sticky in the sun.

I can't imagine why anyone would do such a thing? I got it from an estate sale along with many other items.

 

[tashasdaddy]

Re: removing tar from aluminum hull?

sure sounds like roof patch. gas or sprits, elbow grease, pressure washer.

 

[freddyray21]

Re: removing tar from aluminum hull?

they probably did it to fix a leak. If you take it off it will probably leak, but then you can fix it properly. You can get a heat gun used for stripping paint off of houses. It will soften it and let you get the majority of it scraped off then follow up with mineral spirits, turpentine, laquer thinner ect for the rest.

 

[tashasdaddy]

Re: removing tar from aluminum hull?

i had just thought of the heat gun.

 

[Bondo]

Re: removing tar from aluminum hull?

Kerosine or Diesel will cut the Tar just as Good as Gasoline,......
And,....
Both are Much Safer to use........

 

[gcboat]

Re: removing tar from aluminum hull?

Absolutely stay with Bondo's suggestion - avoid gas at all costs. Also, the heat gun is a great idea but be careful. It will warp that thin plastic hull in a second.

 

[floatingwoody2006]

Re: removing tar from aluminum hull?

I have used Zippo lighter fluid to remove tar, glue, and bugs in the past. Of course i didn't have a large enough area to be overly concerned with combustion. Stuff works great though..

 

[paul2112]

Re: removing tar from aluminum hull?

I remember when my dad worked for the city as a mechanic service writer they used to take the road tar off with diesel .Works fantastic, and cheapest around per gallon..

 

[reelfishin]

Re: removing tar from aluminum hull?

It sounds like I'll be spending the next few days scrubbing and scraping tar.
I don't think they did it so much to stop leaks, it's one there in globs, and not really around the rivets. It don't have may rivets, there are only a few cross braces and the rest is welded. I think they may have done it to quiet the boat down? When I'm done, I'll coat the inside with some good thick epoxy or Gluvit just in case. I've used a product called Interprotect with good results on other boats, its a thick epoxy paint/sealer that is easier to use than Gluvit and doesn't need to be repainted. It gives a light gray finish when dry.
I'd like to polish up the outside to it's original shine. I did a small area and it comes up like new. This boat hasn't seen water in over 40 years, it's sort of neat looking being made of that shiny, hammered aluminum.

 

[reelfishin]

Re: removing tar from aluminum hull?

I tried heat, it don't due much to soften this stuff, it's coming off in chips and flakes. Even gas is slow to melt it. I think it may be auto undercoat with some sort of paint over top to keep it from getting sticky. It's been on there so long it's dried out. The worst part is that the hull is near mint underneath it all. It don't have that many rivets, and the seams are all welded. I don't see why they did this other than to maybe deaden the sound.

 

[reelfishin]

Re: removing tar from aluminum hull?

I found a few ways to melt this stuff, first, carburetor cleaner does the best, with brake cleaner being a close second. The problem being that it would take a few cases of those little spray cans to get the job done.
What I did to get the bulk of it off was to use gasoline and to let it soak for a while. I turned the boat over so that the majority of the lower hull laid flat. I ran a bead of good silicone around the outer edge, then adhered an old piece of garden hose to the hull forming a trough in which I could pour on the gas and let it soak in a bit. Then as it loosened the tar, I scraped it up with a plastic scraper like the ones that you use for body filler. The tar melted long before the gas attacked the silicone sealer. I then just peeled off the hose and silicone and did the sides with some 2+2 carb cleaner and athe same for the forward bow area. It took about 4 hours but it came clean. The worst part was getting the tar out of the textured parts of the hull. (Picture an old cooler with that hammer tone looking aluminum finish).
I plan to give it another wipe down but it should be good as new soon.
The worst part is that the lower hull is good with no corrosion. I found one tiny pin hole but that was made since the tar was put on. I'm just glad they only did the bottom surface. I still have some upwards drips and stains to remove, but the carb cleaner will do the trick for what is left.