I have cleaned and re-waterproofed 5 of my bell tents that are going to be hired out this summer .... still got 15 bell tents to do so I have devised a method that I feel is the most efficient and effective, however things change and I'm improvising as I go along! This is the method I am currently using for cleaning and re-waterproofing a 5m cotton canvas bell tent with a zipped in groundsheet. WARNING: This cleaning method is likely to result in the canvas losing it's natural ability to repel water therefore you will need to apply a waterproofing agent following cleaning. Once you have applied a waterproofing agent, it is likely that you will have to do so on an annual basis.
1. Brush off all dried debris from the canvas section of the tent.
2. Remove all guy lines and unzip the canvas from the ground sheet
3. Soak the canvas in a large vessel (I use a water butt, but apparently a bath does the job too!) filled with hot water and at least 2kg of Vanish Gold. I have also used a cheaper alternative, Astonish Oxy Active Plus and that seems to work just as well. Leave to soak for at least 24 hours, longer if possible, agitate the canvas in the water as much as possible whilst it's soaking otherwise you'll get an uneven pattern on the canvas.
4. Rinse with clean warm water and remove the canvas, leaving it spread out if possible until semi-dry. I use a trampoline to spread tents out to dry whilst it's not being used! Crawling inside a slimy, cold and wet bell tent to assemble it is not a pleasant experience so it's best to leave it to dry for as long as possible.
5. Zip the canvas into to the groundsheet, erect the bell tent to make sure it's clean and dry. Attach the guy lines and peg the tent out.
6. Place a pair of stepladders inside the tent, loosen the guy ropes, remove the door frame and the central pole. Sit the central cone atop the stepladders so that the tent is 'semi-erect'!
7. Apply Fabsil (reproofing treatment) to the cone and work your way around the tent, removing your shoes and without letting your dog jump all over your nice clean canvas. Fabsil can be applied using either a brush (painted on) or a spray. I have used both and there are pros and cons of both methods. The spray method is only good if there is no wind at all, otherwise the spray goes everywhere, you'll use more Fabsil and you may waterproof your grass. The brush method is harder work. I have used approx 7 - 10 litres for each 5m bell tent and I now usually spray the top half and paint the walls.
8. Once you've painted / sprayed as low as you can go, remove the ladders and reinstate the central pole (you may end up with waterproof hair at this point as you can't help but brush your head on the canvas when reinstating the pole). Reinstall the door frame and tighten up the guy ropes.
9. Brush or spray the rest of the tent, including the 'windows' and door.
10. Leave up to dry and then pack away for your next trip! Run yourself a hot bath (without Vanish Gold), get in it and soak those weary muscles!
If anyone has any comments or hints and tips that I haven't mentioned, please feel free to let me know :-)