Pin holes in floor

[acfortier]

Recently had a couple big patches put in on my Comanche, but noticing that I have several smaller pin-sized holes still on the floor. I don't think it really warrants cutting out/welding since they're so small, but wondering what other folks have used.

 

I looked up All Metal/Lab Metal, seems promising. I was thinking of POR-15, using one of these metal fillers, then POR-15 again.

[AZJeff]

A "pin hole" to me is something of about 1/8" in diameter or less.   Under that definition, I would drill them out to be round (assuming they are not) and them put a "pop" rivet into the hole.  Then coat both sides of the rivet with automotive body seam sealer.

 

If there a  bunch of pinholes all located near each other, i would not recommend this approach, and I would install a proper patch in the sheet metal instead.

[gogmorgo]

Usually a pinhole happens because the metal is getting really thin. Not always but often that will be the case. If the metal feels soft when you push on it you’re probably best off cutting out the thin section and replacing.

If not, you can put a quick little tack weld on the pin hole. I’ve also “repaired” rough spots and pinholes in aluminum or steel fuel tanks by cleaning the surface really well, smearing with JB weld, and sanding smooth. Holds up just fine and haven’t had one leak yet. You wouldn’t even know it was done after primer and paint.

[89 MJ]

It’ll take you probably about the same

amount of time to cut it out and replace it as it will to mess around with some of these other “fixes”

[ghetdjc320]

Por15 silver is your friend. Mask off the back side of the holes first.

[Salvagedcircuit]

With a grouping of small holes, I would either cut it out and patch it with new metal or widen the hole with a punch and use a elevator bolt as a plug, then weld it on up. For very tiny holes I wire wheeled, cleaned the spot with alcohol, applied the por15 prep, applied por15 then covered in 1k seam sealer.

[ghetdjc320]

https://por15.com/pages/faqs

[acfortier]

I didn't even know POR-15 came in different colors! That is perfect, thank you @ghetdjc320

[acfortier]

Had time to wire wheel the rust to prep for POR-15. More holes popped up, not surprisingly. These are the size of the holes I'm dealing with:

 

 

Some slightly larger than a pin hole, but I'm going to use the silver POR-15 + tape behind and see if I can get them to fill up.

[Salvagedcircuit]

4 hours ago, acfortier said:

Had time to wire wheel the rust to prep for POR-15. More holes popped up, not surprisingly. These are the size of the holes I'm dealing with:

 

 

Some slightly larger than a pin hole, but I'm going to use the silver POR-15 + tape behind and see if I can get them to fill up.

I'd definitely remove as much of the original seam sealer on the bottom of the cab as you can. On mine, it seemed like they seam sealed before painting and there was rot hiding underneath.

A cup wire wheel on a grinder makes removal a breeze. wear goggles and a mask. protect your glass with cardboard or newspaper so wire wheel strands don't scratch / embed into your glass. A flat 1.5in razor scraper also works well. It is slower but makes a more controlled mess.

[ghetdjc320]

Do yourself a favor and keep removing all that seam sealer. Especially the this giant blob in the corner. A multitool with a caulk blade works exceptionally well for removing the old sealer. I suspect you will find a lot more problem areas

 

 

[OldManComanche]

I have had good success with patching small holes with epoxy.  Try to get as much of the rust sanded or removed as you can. Having something solid to bond to seems to work best. You may want to treat it with a rust retardant. Then I use a good epoxy and 2" wide masking tape to form a patch. I usually start with the lower side (bottom) if you can get to it. Put a small blob of epoxy on the tape and center the epoxy blob over the hole and apply the tape to the repair area. I try to leave the epoxy a little thicker where the hole is. The tape keeps the epoxy from running and keeps it in place till it dries. It may take several applications to fill all of a larger hole. Normally a 1/8" hole will be around a nickel to quarter size epoxy patch. The epoxy likes to run down hill till it sets up, (the reason for the tape). I have even patched holes on the bottom side of the metal, and the tape keeps the epoxy from dripping off till it sets up. Peel the tape off when it hardens. You can grind or sand to finish the surface. I haven't tried to patch a large hole, but I don't see why you couldn't glue in a piece of sheet metal to fill a larger hole.

This isn't real fancy but will work!

[gogmorgo]

JBWeld is an epoxy 

[Pete M]

for the 88 I'm working on I coated the top and bottom around the weak pinhole areas with POR15 and later added a blob of seam sealer to top and bottom.  mostly because those were the tools I was using for other areas anyways and so they were on hand. 

[ghetdjc320]

Once you try to fill 1/4” or more of a hole or gap, some sort or reinforcement is advised. You could use a good short strand filler like evercoat fibretech using the tape method advised above after applying por15 black. But first, keep at your seam sealer and strip it all out. I suspect you will find a TON more rust hiding in the atrocities know as MJ factory spot welded seams. If you don’t get it all removed, you will never be able to get to or eliminate that cancerous hidden rust. 

[OldManComanche]

JB Weld is your FRIEND in times of distress!