I bought a 78 F150 and of course the comment was made "very little rust". At the time of the sale. Well after I pulled out the carpet I found two big a$$ holes on the driver and passenger side. I have spot wielded the hole with sheetmetal but I still have smaller holes around the wield and a few dime or smaller holes. Is there any type of sealant that can be used to fill in the tiny gaps to keep as much water out as possible? I would have posted pic but the fourm says I cannot.

 

Even though the holes are dime sized you should still weld them closed and treat them with sealer to prevent future problems.

Just make some sheet steel plugs or use fender washers or regular washers and plug weld them.

 

Roger that. I didnt think about using washers. What type of sealant do you recoment?

 

Once you are done welding and dressing the welds ( grinding them so they are flush as possible with the floor ) go to an autobody shop ask them for seam sealer.

It's NOT for plugging holes it's used after you weld a seam to waterproof it.

You can apply it with a brush it's thick stuff but works and is meant for bare metal, then you shoot the spray sealer on the bare metal or two part epoxy primer.

Or you can go cheap with duplicolor green metal etching primer, pep boys i think is the only one that carries it now, grey primer, then primer sealer and paint.

Under 100.00 for everything and you have solid floors that will last the life of the truck if done right and maintained.

 

Thanks GQROD. I will follow your advice. It will take me some time to seal up all of the spots since I only have a stick wielder. I set it on 30 amps which is the lowest setting. It burns up the sheet metal in some places making more holes! LOL but If I take my time i should seal them. Slow go.

 

The trick is to start the weld on the fresh thick metal then finish on the thin metal, this way the thick metal acts as a heat sink and absorbs some of the heat, then when you finish at the thin metal you stop and you don't get burn through.

Thought you had a mig or flux core welder which would have made it a little easier.

However if you get too much burn through, use a washer on the top AND the bottom of the hole.

Use a bolt to hold it with the old metal in beteen the new washers, this way it aborbs more heat, and if you get burn through on the old metal you can let it cool then make another pass over the hole to plug it with the bottom washer acting as a support for the fresh weld material.

You can make the washer on the top smaller than the one on the bottom like a pyramid so that it can support the new material in case of burn through to allow you to plug it without burning too much metal.

Go to a REAL welding supply place near you and pick up a pack of EASY STRIKE 1/16th inch thick welding sticks. Should cost $12.00 with enough to weld a whole frame if you needed.

this brand is THE BEST for such low amp stick welding, does strike an arc easier and burns cleaner than the lincoln brand sticks DON"T waste your money on the lincoln sticks they SUCK especially the 1/16th inch ones, they never strike and are just turds.

One last tip,

To fill the hole you use a technique i came across from tiral and error

If you have ever seen someone fill a cone with ice cream at an ice cream shop, they start around the bottom and quickly build it up to the point.

Do the same thing,

Start around the edge and quickly keep moving the puddle in a circle moving INWARDS in a circle until the hole is plugged.

With stick welding practice makes perfect so don't give up just keep practicing and learning what works best for your particular situation.

When learning a angle GRINDER is your best friend, get one TRUST me you will be using it to get off all that metal you are putting on, just have fun and be patient with your learning.