Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Waterproofing a Carradice

Has anyone found a way to make a carradice bag (Nelson) truly waterproof and ideally not absorb any water either as to not weigh down the bag. I was thinking about some sort of spray, but if there is anything that works better, lemme know. Also, if anyone has any good experiences with a particular spray-on treatment, i'd love to hear what worked. thanks -leo

You could certainly try spraying the bag with a water repellent compound. Look at an outdoor store for available products. But don't expect miracles. Water repellent sprays generally work by increasing the surface tension of a fabric so the water beads up. It may slow the entry of water, but eventually the water will win.

You can also get wax to rub into the fabric to restore it's original weather resistance. Probably a better route for cotton duck material.

Nonetheless, cotton duck is generally not 100% waterproof. You have to expect it to eventually soak up water and seem a little. I really don't think a little water in the fabric is going to make any noticeable difference in your riding performance anyway. If it's raining, you should be slowing down anyway!

For protecting the contents of the bag, I like to use a plastic trash compactor bag to line the inside of my Camper Long Flap. Trash compactor bags are extra strong so the stand up to nore use than a regular trash bag.

Plus the seams, unless taped, are wicking monsters for moisture, the water just pours in from the holes through which the thread is sewn.

Cotton swells when damp, so the holes tend to close up.

Waterproof is a big ask of natural fibres. Stick with Ortlieb if you are going to get hung up on waterproof.

Carradice sell a wax (http://www.carradice.co.uk/accessories/other.shtml)for re-proofing their cotton canvas.
I use Barbour jacket wax.
The easiest way to apply the wax is to melt the tin over a water bath and dab the wax onto the clean, dry, warm canvas esp the seams. Blast it with hair dryer to really impregnate the fibres.
Any excess wax on the surface will soon wear off.

I use Chap Wax

Cotton swells when damp, so the holes tend to close up.

Waterproof is a big ask of natural fibres. Stick with Ortlieb if you are going to get hung up on waterproof.

Exactly.

Carradice are beautiful, high quality, and very classy, but not entirely waterproof. It's just canvas, like an old tent. They leaked.

Bockman and MichealW are right. Here's how I sealed a canvas rucksack to reasonable watertightness:

Heat it in the oven to very warm. Melt SnoSeal in the microwave and use a paintbrush to paint the hot bag on the outside, paying special attention to all seams and stitching. It will soak thru so no need to do the inside. If you do, you may find some waxy residue on your belongings in hot weather. SnoSeal does not harm canvas or stitchings. Test it for color changes first. It darkened the old bag, but not to an unpleasant degree. You can 're-activate' it by re-heating and applying additional light treatments later, probably only to the top and seams.

Filson's outdoor clothing and Barbour are very good products and are referred to as 'oilskins'. SnoSeal is available at Sears shoe dept or just about any Work-n-More store for about $5 a jar. You get about 3X as much as the Carradice wax.