I am trying to remove the rust from inside my steel frame. There are, however, a few small holes in various places along the frame. Any tips on how I can make these water tight so that I can fill it with vaporust and leave it overnight?
Don't make your frame water tight. That will only make your problem worse.
It's unfortunate to see a frame go bad due to internal rust, but it needs to remain unsealed.
The reason for this is that moisture will find its way in and needs a way out. Even if you never ride in the rain, condensation of water vapor alone will allow liquid water to accumulate inside the frame.
Most frames (I believe) have small drain holes near the bottom bracket for this reason alone.
Here's a nice little post from Gunnar about why their frames have drain holes: http://gunnarbikes.com/site/2012/06/draining-your-bike/
Here is what I would do.
Identify all the openings
- Strip the frame of everything (including headset)
- Start covering all of the obvious holes with ducktape and leave one open (BB or headtube)
- Use something to pressurize the frame (air compressor or bike pump) in one opening that you left on the frame, use ducktape to seal around.
- Start blocking all the holes you find with small portions of ducktape till you find all holes.
Just one method to find the holes. You could use water to find the holes as well.
For the sealing of the holes:
Blocking the holes for the Evapo-rust, I would take an old inner tube and start cutting it up into small pieces. Using a big fist full of zip ties I would start replacing the small pieces of ducktape that is covering the holes with a gasket seal made with the cut pieces of inner tube and the zip ties. The zip ties will be used to provide compression against the inner tube sort of like a band-aid. You can plug holes in areas that are not uniform by folding up the inner tube to compress into the areas.
For the head tube and bottom bracket you could use small square pieces of wood with a piece of inner tube cut and flattend out on the wood to put on both sides of the opening (you will need 4 square pieces of wood and 4 square cut pieces of inner tube). You can use the zip ties to pull the two pieces of wood together compressing against the top and bottom of the head tube and both sides of the bottom bracket.
This will create a water tight seal and you will not have to deal with tape all over the place that might not hold the liquid.
I have used this method to repair transmission cooling lines on a truck broke down on the side of the road on the way to a bike race!
If you can, take more than one day to soak your frame in vaporust/framesaver/etc. Set your frame up in one orientation, then roll it to another axis every 12hrs or so (it's not an exact science, don't bother setting a timer).
Electrical tape over the smaller drain points on your stays and your bottom bracket, but tape a good pad of paper towel over the larger points (seat tube, head tube, bottom bracket shell points). This will save your flooring in the long run instead of worrying about a watertight seal.
I roll on steel myself and try to hit my frame with framesaver once a year.