internal frame rust protection. feedback on idea

[saltydawg]

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?

[Socal Tom]

I've seen people dip a rag in rust preventative and push it through frame. You will probably get better coverage that way vs spraying it in from the sides.

[saltydawg]

I've seen people dip a rag in rust preventative and push it through frame. You will probably get better coverage that way vs spraying it in from the sides.

The eastwood internal frame coating comes with a 2 foot or so spray tube with a 360 spray head on the tube. It sprays around the entire frame, top bottom etc. I used it on my tacoma and it works well, I looked in the holes when I was done to check for coverage.

https://www.eastwood.com/eastwood-inter ... rosol.html

[MickinOz]

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?

My thoughts:
Use big mutha Tek screws.
They tap their own thread.

Ya have to be a bloody good welder to get a totally water tight frame using tube welded together.
Maybe you are, but if you don't get it right you get water in and it takes forever to dry out again.
All the while quietly rusting away.
It might actually be better to drill a couple of drain holes in each frame member and leave them open.


If your frame is not made from galvanised steel, use zinc rich primer.
Over here, we can get several primers that contain rather a lot of powdered zinc metal.
I'm talking primers that give you a surprise when you pick up a litre can and feel the weight.

zinc primer.JPG (43.95 KiB) Viewed 1746 times

The zinc is there as the metal, not some compound.
They provide galvanic protection in a similar way to hot dipped galvanising.

The thing about electrically (galvanically?) connecting zinc to steel is that it provides some protection remotely.

The other thing you can do is get some anodes from an outboard motor (the ones meant for seawater, not fresh water) and bolt them on. I have found this worthwhile on a boat trailer that was getting old and had lost most of its sacrificial zinc coating, buit not so effective on a land trailer.

[GPW]

We have used Fluid Film in our 1969 SAAB restoration … We used it for the “inner” places … Very effective , non-toxic , and also comes with a 2’ tube in the kit … We also use CRC Marine corrosion inhibitor … sorta like cosmoline … Others have used chainsaw Bar and chain oil …
Where we live , if you don’t treat it , it WILL rust !!! …

[saltydawg]

I am not a great welder, thats why I will be putting seam sealer on the welds. I know about fluid film, that would be the retreat item in a few years. I did think about tek screws, but tek screws like to drill thru one metal in to another layer to hold they dont like to hold single layers of thin metal well.

I have used the zinc rich paint before on a water tower, 50lbs of zinc, 10 lbs of epoxy paint in a 5 gallon can. Boat zincs need to be wet to work, preferably with salt water, that why they dont work that well in fresh water. They make Magnesium one for fresh water.

I have thought about just drilling drain holes, but with out truly being able to coat the inside of the frame with a rust preventive, I know the metal would rust and I could not see or do anything about it. If I could get it galvanized for a few hundred bucks I would but I assume its much more expensive than that.

Sarcasm time. Maybe I will just hook up an argon tank from my welder and purge the frame non stop.

[twisted lines]

Where we live , if you don’t treat it , it WILL rust !!! …

Where I live, when outsiders visit with 10 year old trucks we stop and admire them in parking lot's

[Ottsville]

I have a 20 year old utility trailer with 2x3 tube which have plugs cut out and welded in the ends. I have no idea what the inside of the tubes look like after 20 years, but I wouldn't even worry about it. Your frame will outlast what you are using it for most likely(unless you are dragging it through saltwater maybe). You could always build your trailer and have the whole thing galv-dipped.

I don't understand why so many people choose tube over channel.

BTW @Saltydawg, nice job on your trailer

[saltydawg]

I have a 20 year old utility trailer with 2x3 tube which have plugs cut out and welded in the ends. I have no idea what the inside of the tubes look like after 20 years, but I wouldn't even worry about it. Your frame will outlast what you are using it for most likely(unless you are dragging it through saltwater maybe). You could always build your trailer and have the whole thing galv-dipped.

I don't understand why so many people choose tube over channel.

BTW @Saltydawg, nice job on your trailer

First thanks for the comment on the trailer.

As for channel over tube, or vise versa. Channel rusts out too, look at most trucks over a few years old. Channel allows easier coating, but allows mud puddles to form in the frame. Tube, coated and sealed while it will rust inside but if well sealed should keep it to min. If I was doing a lot of water crossings it might be different.

Between seam sealer, paint and welds my frame should be pretty darn water tight.

[Ottsville]

Saltydawg, I've gathered, maybe incorrectly, that you are in Virginia. I don't know if you know or not, there is a manufacturer of panels out in Fork Union and they do sell direct. (but they are limited on size)

https://www.carbon-core.com/

[saltydawg]

Saltydawg, I've gathered, maybe incorrectly, that you are in Virginia. I don't know if you know or not, there is a manufacturer of panels out in Fork Union and they do sell direct. (but they are limited on size)

https://www.carbon-core.com/

Close maryland I am doing my own panels due to wiring and internal to the panels steel frame although the frame is limited

[aggie79]

Why not drill holes in the frame and spray in closed cell polyurethane foam such as Great Stuff? The closed cell foam should waterproof cracks and openings and the closed cell foam won't absorb water.

[saltydawg]

Why not drill holes in the frame and spray in closed cell polyurethane foam such as Great Stuff? The closed cell foam should waterproof cracks and openings and the closed cell foam won't absorb water.

That is a great way to make it rust out. The foam does absorb a microscopic amount of water, but mostly it holds the water right against the metal. Years ago a few car manufactures use spray foam in certain areas to sound deaden the body, they all rusted out there.

[MickinOz]

Boat zincs need to be wet to work, preferably with salt water, that why they dont work that well in fresh water. They make Magnesium one for fresh water.

I realise it is irrelevant to this discussion, but I want to clarify something, just in case someone is reading up on galvanic protection for some other purpose:

Zinc anodes for outboard motors don't work well in fresh water because, in fresh water, zinc is actually in the wrong position relative to aluminium in the electromotive series of the elements. i.e. in freshwater, zinc is less prone to oxidise than aluminium. Bolting a zinc anode to aluminium in freshwater can accelerate the corrosion rate of the aluminium.
In saltwater, zinc is more readily corroded than the aluminium and it is generally cheaper than magnesium.
In freshwater, magnesium is more negative than zinc, hence freshwater anodes are made from magnesium.

When it comes to protecting iron, zinc is way further up the series than iron, whether it is fresh or salt water.

All this assumes my chemistry lecturer didn't bullshit me when I asked him to explain it.

[twisted lines]

Ok the OP is in
How about freshwater and controlling the power down the cable's of downriggers using zinc.
Freshwater guy's have deep water too especially here.