Pinhole Repair

[natemoen]

So I had recently acquired a Venturer tank. When I got it, it looked amazing. Inside was super clean. The paint thpugh was super thick and gooy. After lots of stripe and laquer thinner I found out why the paint was so thick. It was to cover up all the JB Weld and epoxy paste used to fill the the plethora of pinholes...

So, since it is a Venturer tank I am not going to let it go. So that means it is time to start filling holes, and lots of them!

So to start off I took the tank down to bare metal and sanded the area with 60 grit sandpaper so that there would be something for the metal filler to stick too. I then took a automatic center punch and used that to pop out the epoxy and to dimple the area around the hole.





After finding and opening all the holes up I cleaned and sanded the area again. For now I am using up some lead free body leading compound, you could also use solder for this and I will end up having to use some solder anyways.

On a safety note: ONLY use LEAD FREE compounds or solder. You will need to be standing this and if you sand leaded material you will then have lead in the air and you don't want to be breathing lead in. Wear a mask ot respirator no matter what though.

At this point apply some leading butter or flux depending on the filler you are using. Heat the area around the holes nice and hot, I am using a small butane torch for this. Then apply the filling compound and just keep going filling holes. As the area gets hot your butter/flux will start burning. Let things cool some and hit it with a wire brush to knock off any loose filler and them wipe the area clean again and put some new butter/flux on. Then just keep repeating till you have all the pin holes filled.

Now since I don't have the paddles for body lead it ends up a bit clumpy, more like it would if you are using solder. You can get it pretty smooth if you have the paddles. So it will look a lot like this.





At this point you can take a rasp or a bastard file to it and start bringing it down to smooth it out. As you go you may find some holes that didn't get filled in completely and you may need to redo some. After you have it all filed down sand it for the finishing touches. I would suggest filling the tank with gas at this point and letting it sit to make certain all the holes are filled and sealed. Also especially in this case with so many holes like this tank I would put a liner in the tank. I personally use Red-Koat epoxy liners and have never had one fail. You can treat the tank as you would any other tank once you have all the holes filled when it comes to paint.

I will keep adding pics as I go along and fix this tank up.

[GLoweVA]

Wow

It looks like someone hit it with a mini shotgun!
I've never seen so many holes before.

+1 on keeping the venture tank. I would too.
But, whew, that's a lot of work, but worth it.

I wonder what would cause that much pitting?

What did the painted outside look like? Could you tell that it was pitted, or did the paint cover up all that.

Makes me wonder if my tank is that bad too.

[crazy steve]

You've got a project there... good luck with it! And for sure a tank seal is in order...

[natemoen]

I wonder what would cause that much pitting?

What did the painted outside look like? Could you tell that it was pitted, or did the paint cover up all that.

Makes me wonder if my tank is that bad too.

Paint on the outside looked ok but was bubbled on top (no holes on top though), it was repainted black. I don't know if the seller owned the bike or if it was just a wrecker parting out the bike. It had obviously been buffed up for the sale though.

Guessing since the tank was so clean inside that someone got a little over excited with some acid when cleaning the inside.

This is a very good example as to why you should take a tank, especially a reprinted one, down to bare metal before you repainting it.

[fredintoon]

Hi Nate,
double-posting for those who don't see .org.
Been there, done that, screamed like a girl when the solder ran onto my wrist.
Honestly, with that many holes I think the tank may well be FUBAR but I hope you succeed with it.
Yes to using lead-free solder and wearing a breathing mask.
But your technique needs work.
Whack the dents deeper with a normal center punch and a medium hammer, the automatic center punch ain't doing the job.
Scuff up the dents with a mini-wire brush in a Dremel tool.
The solder blobbing up like that shows the work is too cool.
First and foremost, slather the dents with resin based flux. No such thing as too much flux.
Heat the tank with a Bernz torch as you apply the solder with the most powerful electric soldering iron you can buy.
If the work is hot enough the solder should flow into the dent smooth and flat like rain into a pothole.

[trbig]

If the work is hot enough the solder should flow into the dent smooth and flat like rain into a pothole.

So what keeps it from leaking out of the hole into the tank if it's that fluid and you've made the holes that big?


Also, I've got an XJ tank with more pinholes in it than that tank has, so I'm interested in this thread. I can't just throw the thing away..

[clcorbin]

So what keeps it from leaking out of the hole into the tank if it's that fluid and you've made the holes that big?

Surface tension.

[fredintoon]

So what keeps it from leaking out of the hole into the tank if it's that fluid and you've made the holes that big? - - -

Hi Tod,
you don't punch the pinholes larger, you punch the pinholes inwards to make a dent around the hole to catch a big smear of solder.
And like Clint sez, surface tension stops the molten solder from pouring through the pinhole.
If you'd punched the pinholes out to the size of (say) a .22 bullet you'd be soldering patches over the holes because surface tension ain't that good.

[natemoen]

As stated surface tension does hold the filler there. BUT if you get it hot enough even that doesn't hold it there and it all slips right down in the tank. I have a lot of little bits inside the tank at the moment....

As to Fred's concern about the large blobs, I do not want to heat up a large area of the tank at a time. I am trying to keep the heat down to a minimum to prevent any possible warping. I am using a very fine tipped butane torch to just heat a very small area and then I apply the filler and get out of the area and go work elsewhere on the tank. That way the filler cools fast and nothing stays molten for for than a second or so.

Fred's other concern about the center punch not making a big enough dent. If I were to make larger dents? If I were to go that route, I could just take a hammer and punch in the bottom of the tank. There are too many holes to go making large dents at each hole.

Here are some more pics after almost all the holes have been filled.

















I started sanding some but didn't take any pics of it after that.

Anyone have any suggestions as to something I can swish around in the tank to help dissolve the epoxy that was squished through the holes?

[CaptonZap]

Methylene chloride.
It will soften epoxy, but it won't desolve it. Nothing I know of does. CZ

[T99Ford]

Nate, check out Caswell Plating's tank liner. It is terrific stuff, from the firsthand experience I have with it. It is a two part pour in, but is miles beyond Por15 or Kreem. I lined my VTR tank with it, and I have a friend who lined a handbuilt fiberglass tank with it about two years ago. Both liners are as good as day one, and it is easy to do. Caswell even says that it can be used to repair old failed Kreem and Por15 liners, so I would bet it would seal up the epoxy you are describing.

[Dragon Tamer]

As Fred pointed out, your work temperature is too low. Not only does that make the solder lumpy there is the greater problem that it also does not adhere or bond well at those temps and may leak or just fall off at some future point. That tank may be beyond repair as it looks to me that it is very thin/weak in many places. You may be able to get it to stop leaking but keep a very close eye on it after you get it on the bike as I would bet that with vibration and the weight of the gas it will start to leak again shortly. You are better off to make large puddles of solder and cover many holes at once than to make small ones on each hole. The large puddles will add strength to the tank and make future leaks much less likely. Also using a tin/antimony/silver based solder is MUCH safer and stronger.

[scoot]

Although that metal seems very thin, the tank liner should nullify the potential of the solder separating, no? A solid tank liner should be able to seal a wicker basket (although not add structural strength).

Another thought, loose lead under your new paint?

scoot

[natemoen]

Any loose material will come off as I sand it down. If it can handle being ripped at and vibrated around by an orbital sander and dremel I doubt it will be any more likely to come off later on down the road.

[Lonerider62]

Wow, I sure do admire anyone who has the patience and skill to do a repair on a gas tank like this, that has the damage this one does. I guess I'm not as determined as some because I probably would have canned the thing and let it go to the scrap yard. I guess if the person who is repairing it will also be the person who uses it, it's OK but I don't hink I could pass something like that on to another person who who had expectations that it was going to be leak free for a long period. Even if all the repaied holes are good, I'd expect there are places not yet discovered that will end up leaking.