Rust protection inside the frame, idea

high-and-dry

Active member
Okay my frame is all 2x3 rect tube. I have a few spots I have put 1/2" round tubes in thru the side of the rect tube to be able to use the frame to run wires. But I know tubes can ( will ) rust from the inside out ( I own an old tacoma ), my plan is to use the wire entrance tubes to spray eastwood internal frame coating. I cant get in to every tube of the frame, and spray tube that comes with the frame coating is not long enough.

So my plan is to drill holes on the bottom of the frame where I need to and tap the holes 3/8-24 ( it works out to about 12 holes) and after spraying the coating putting in the screws then when I paint the outside of the frame just paint the screws over to seal them. This should allow me remove the screws if needed for inspection and or recoating. It might only be every few years to inspect but the frame will probably need paint that often anyway.

I plan on sealing the wire tube after the wires go in the frame, as well as using automotive seam sealer over my welds before I paint the outside of the frame. The idea of the seam sealer is if I have any pin holes or gaps in the welding and to fill where my welding is not the best to try to not give rust a place to start. Basically I am going for a water tight frame, that is protected on the inside.

Opinions or thoughts?
 

NatersXJ6

Explorer
Better to leave the holes open big enough to drain, save on the tapping, bolts, etc... I would use bigger holes, 1/2 or 3/4.

It is virtually possible to prevent dust from getting in and becoming mud then rust, but relatively easy to make openings big enough to allow pressure washing out and draining to dry, with a good coating you can drastically slow rust.

Or have it galvanized.
 

high-and-dry

Active member
If galvanizing was only a few hundred bucks I might do it, I dont know what it actually costs.

If I thought I could get a complete coverage of the inside of the frame with a coating I might leave it open to drain, but I know I would not be able to get a complete coverage with out dipping the frame. Heck trucks rust out with drain holes and being dipped.

The plan is eastwood coating now, and in a few years open it up and give it a fluid film coating and re seal.
 

NatersXJ6

Explorer
If galvanizing was only a few hundred bucks I might do it, I dont know what it actually costs.

If I thought I could get a complete coverage of the inside of the frame with a coating I might leave it open to drain, but I know I would not be able to get a complete coverage with out dipping the frame. Heck trucks rust out with drain holes and being dipped.

The plan is eastwood coating now, and in a few years open it up and give it a fluid film coating and re seal.

The last time I had something galvanized it was about $300 for a 61 Land Rover chassis about 10 years ago. I think I spent $200 more on sand blasting before dipping. If you aren’t designed to dip, you can’t or won’t galvanize successfully. Closed in tubes typically can’t be dipped because they can build pressure and explode / fail.

I lived in Michigan for many years, I know how rust progresses, but I still think you are better to have things open and cleanable than closed in.

Good luck with your project though! It sounds like fun but a lot of work. Maybe do a galvanic protection device tied to an onboard battery?
 

DaveInDenver

Middle Income Semi-Redneck
Completely concur with advice so far. I've done Eastwood internal frame coat on a couple of frame and do annual Fluid Film (similar to Wool Wax) on my frames. Do not fall into the fallacy about spray foam, it's a guarantee of rotting from the inside out. You want to keep clean, let drain and periodically coat with anti corrosion.

If you do use the Eastwood stuff cover the floor, it's thin and will ooze and drip. If it gets on the floor, or anything else, clean it up immediately otherwise it's permanent.

IMG_0993_mid.jpg

On my steel frame bicycles I've used LPS #3, which sprays in fairly thin and builds up a waxy coat. It's kind of the less old school to real old school boiled linseed oil. It's not the fancy new school CorrosionX stuff. I got a can of the CorrosionX, smells like oily peanut butter, weird smell. Seems to work alright, though.
 
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opp

Observer
ottsville said:
Can foam holds moisture against the metal.
WE use the expanding foam as glue how would water get in there ? not being smart would like to know
 

ottsville

Observer
The expanding foam is considered open cell foam. Those open cells trap water. I know someone that used the spray foam to insulate a vehicle between body panels. It rusted from the inside out.

I've seen pole barns where spray foam was used on the inside of the roofs. When moisture got between the metal and the foam, the foam held it against the trusses which then decayed and collapsed
 

DaveInDenver

Middle Income Semi-Redneck
You need to use the right stuff. Some sprayfoams are not waterproof.
Seems like appropriate waterproof expanding foam is probably not going to be found at the Home Depot. Like maybe a 3M 08463, which is made to seal cavities in vehicle bodies? It's got to be semi-rigid or flexible and able to withstand the temperature swings and chemicals, too.
 

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