Floor Brace question...

[TimE]

On the front floor brace on the drivers' side under the pan, what is the purpose of the hole on the bottom and the one on the rear? I assume it is for drainage of moisture accumulation but what would happen, long term, if I were to weld these up and completely seal the brace to the floor pan?

The reason I ask is after removing the floor in my truck there was quite a bit of sand and debris inside of the brace that helped to retain moisture. Once the truck is reassembled, it will be used as a truck(i.e. dirt roads, rain, etc.) plus I live in a humid part of the country not too far from the coast. I don't want to weld the holes closed and seal it just to create another moisture trap for hidden rust to occur but on the flip side I don't want to have a brace that will retain crap to cause it to rust either.

Could the brace be modified in some form so that it could be cleaned out rather easily?

I plan to tackle this issue this weekend, in one form or another, so does anyone have any thoughts or experiences with this? I am completely open to suggestions/ideas as to what would be the best route to take.

[100%Chevy]

Tim,why don't you try to find one of those plastic plugs for it?Then you could remove it for cleaning.
On my rear mount,I stuffed a rag in it to keep sand out when blasting.I found it later when I was welding on the floor.Used the hole to squirt water on(or in)the fire,then a clothes hanger to pull the rag out.So,it is somewhat useful!
Mike.

[collins10672]

i have wondered about this too tim.there are several ways you probably could do this.you could put a hole in floor above the brace so you could take a water hose and wash it out later.to seal the hole you drill just put a small rubber plug like some of the newer vehicles have.or you could drill a hole in the backside of brace and put plug there so you could wash it out anytime you want to and the purpose of the plug would be to keep from more dirt filling it back up.there are two reasons that these trucks rusted so bad.one is poor workmanship from factory because of limited drain holes and also the cab was welded together before it was primered at the factory(that is why when you cut off rocker panels that they are so rusty behind them,also if you cut the roof skin loose and looked under there it would be surface rusted also)not trying to give these trucks a bad name because i love this body style and have owned 8 through the years,but the facts are gm didn't do a good job of rust proofing in the 60's.the second reason was plain and simple these trucks were driven on dirt roads,mud caking in the braces,salt,etc. and the owners were not to good at washing underneath.most farmers would just let the rain wash them off.gm didn't plan on these trucks being around 40 years later because if they built them too good they would quit selling new trucks later.i have thought long and hard about the drainage problems they have.i had a 66 that i restored in 1994 and put in new rockers,cab corners,inner rockers and fenders.i drilled drain hole in the bottom of fenders and washed it out ever time i washed the truck and never had a return of rust and the fender braces never packed up with dirt again.so the bottom line is drill drain hole every where you can because if you don't the truck will make its own drain holes(via rust holes).hope i have been some help.

[TimE]

Originally Posted by 100%Chevy

On my rear mount,I stuffed a rag in it to keep sand out when blasting.I found it later when I was welding on the floor.Used the hole to squirt water on(or in)the fire,then a clothes hanger to pull the rag out.So,it is somewhat useful!
Mike.

I think I'll try the plug thing but I think I'll pass on the fire part(I hope!).


collins- This is the same type stuff that I have been considering since the truck is apart. I want to try to fix it so the rust issues won't return, at least for many years.

I think I will do as you guys have suggested and install another plug so I can rinse the area out periodically.

All of the metal that I reinstall that will be welded on and non accessible, will be coated with cold gal. spray. Everything else will be coated with some Zero-Rust coating that I have(at least I think I have enough).

Thanks for the input guys!!

[protrash64]

I was going to suggest the same. In my pick up I drilled extra drain holes in the cab corners(back) because there was a pound of dirt in each one. I dont drive the truck in bad weather. I also found my door drains totally clogged....2 slots on bottom. I think it wouldnt be bad to drill extra holes to get rid of junk and water instead of creating a nice pocket. I also mentioned it in one of the threads where someone had torn their rockers off. That valley created by the weatherstrip ledge and the floor pan needs to drain. Im considering drilling that too.

[LILRED66]

As mentioned in the other posts, design or poor-design, I should say, was a big contributor to the rust issues with these truck. When replacing/repairing the cab supports, cab corners, rocker panels, door skins and inner fenders, I make a concerted effort to provide additional seek holes, to ensure moisture has an escape route.

I wouldn't seal things up entirely, because moisture and dirt will find its way in and with no way out or the ability to breath, it will corrode at a rapid rate. One thing to keep in mind is that it took 30 plus years to rust to this point, so with some preventative measures, it would take another 30 plus years to rust again. I always apply a "weld-thru" primer when replacing panels that can not be accessed after the repair is complete. Also, when I open up an area prone to rust, I spray a liberal coat of rust encapsulator on the areas with surface rust, but not quite rusted through.

I have heard people filling voids with an encapsulating foam and I do not recommend doing this, because it is porous and will hold water, even though the water will not effect the foam, it will corrode the steel.

Good luck with your project and keep us posted with your progress, especially with photos of what you do.