Rust inside frame rails

SNOWBIRD

Amphicar Expert
Every Amphicar, Should have its frame rails inspected, Even if your car is fully restored,, ,DO THIS INSPECTION! 98% have this gunk in the frames. Drill a hole by trans mount large enough to get a shop vac hose in. also drill a hole in front side(outside behind front tire,(weld a nut here later that you can put a bolt in to plug.) Take a garden hose and flush all gunk out, Vacuum up etc. let dry. (this is a messy dirty job>) When finished pour a little oil in to slosh around.
Picture below is from a supposable restored car From Quebec.

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dougklink

Member
I used Eastwood rust encapsulator in the frame rails. It comes with a long applicator tube you put into small holes you drill in the frame rails and it converts the rust and produces a hard waterproof finish.

Every Amphicar, Should have its frame rails inspected, Even if your car is fully restored,, ,DO THIS INSPECTION! 98% have this gunk in the frames. Drill a hole by trans mount large enough to get a shop vac hose in. also drill a hole in front side(outside behind front tire,(weld a nut here later that you can put a bolt in to plug.) Take a garden hose and flush all gunk out, Vacuum up etc. let dry. (this is a messy dirty job>) When finished pour a little oil in to slosh around.
Picture below is from a supposable restored car From Quebec.

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View attachment 2259
 

Jon March

Member
Gord - you are smart to emphasize this important point about a very commonly, and easily overlooked area.

Can you show some pics of the front holes / locations you recommend?
And for people who dont weld - i wonder if a 1/2" rubber expansion plug would be safe to seal the front holes?

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SNOWBIRD

Amphicar Expert
That would work if you put drain holes on inside(You Can), I put on outside will take a pic when I weld nuts on!
 

Jon March

Member
Gord/all - heres a question: do the frame rails end "blind" under the angled footboard...or does the opening continue up into the frame rails on either side of the spare , where the end are open!
......(and dont they need their own cleanouts?, or do they connect into the framerails under the floor back to the trans area, and the entire "z-shaped" frames cleaned from front to back with washout holes front & rear?
 

jfriese

Active Member
Here's how I handled it when I discovered the problem in 2003. I cleaned out any gunk from inside the rails and sprayed some waxy, British stuff inside the rails at that time too. My cars run dry so I leave the plugs out so that warm engine air will dry out any moisture in the rails. If your car runs wet, plug the rails when you're in the water. This system has worked fine with no leaks for 15 years.

John Friese
67 White
67 Red

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Jon March

Member
This is very helpful - With these pics , and Gords comment that the hole "can" be done inside...and not having a welder (and also preferring a location thats easier to get at from "above" )...I think im going to cut 1.5" holes in the floor right where the floor sits on top of the frame, and cut 1.25" holes into the frame (where the red dots are). I can plug them with rubber stoppers that will rest at the same height as the flooring. That will provide easy access to inject Dawn detergent/water/steam cleaner ...and suck it out the back end, in the frame holes i have near the trans mounts. That should give me easy access for keeping them clean.

I guess the frams thats diagonal under the floorboard, and then heads straight to the front are less of a rust issue (are they closed off from the floor frame?
- ive never seen anyone mention tricks to keeping them cleaned out....(or should they have their own (1/2" ?) crud-drain hole as well near to where they meet the floor frames?)

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jfriese

Active Member
I learned of this problem in 2003 when water in a rail rusted through the front area behind a front wheel and dripped on the floor days after the car was otherwise dry. I could have done a patch up there but decided an emergency drain on each rail could possibly be handy occasionally. Normally, if I ever needed to drain a rail I would use a vacuum pump to pull the water out the larger holes. I don't carry such a pump on extended trips though and if needed I could use those front drains to empty the rails. Never have needed to pull water from those or the larger holes in the frame rails near the transmission.

Amphicar didn't think water would get into the frame rails because they thought they had them pretty well sealed up. It wasn't good enough though since all 4 of the frame rails on my two cars either had some water in them or signs of water in the past. I worked on a car whose rails were so bad that when I punched the larger holes near the transmission the rails were completely full of rust right to the top. That rust was so bad that it ate into the rear axle area and froze the swing axle into the housing. I broke a 5lb sledge handle banging the swing axle out on that side and had to grind some of the metal away to get it back in.

It's been a long time now but I don't think the bottom frame rails are open to those front frame members. Those front frame pieces I believe are open in the front trunk area so if you sink your car you would want to drain those too.

John Friese
67 White
67 Red
 

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