Replacing Drascombe cabin windows
Based on replacing windows on a Drifter
by Steve Schlemmer
1. Parts required
1.1. New acrylic windows from Churchouse Boats
1.2. New fixings from Churchouse Boats
1.3. Clear silicone sealer
1.4. Scrap wood and bolt for the clamping fixture
2. Tools required
2.1. Electric drill, bits and countersink
2.2. flat and shaped scrapers
2.3. Stanley knife
2.4. File
2.5. G cramp
2.6. Screwdriver
2.7. 8mm socket
3. Fixture required
3.1. From scrap ply or board and 2x1 or similar make a clamping fixture (see photo) that can clamp the inner frame to the cabin side via vertical and horizontal legs cramped to the cabin locker below the window. Shape the ply or board to give access to all the fixings. To ease handling, attach the board to the vertical with string through the contact point; bolt the two legs together – this ensures that the fixture can be positioned with one hand. Make the fixture before removing the first frame.
4. The original windows were made of an aluminium alloy, secured with rivets. Later boats have bronze windows, secured by a variety of means. Mark the top of the inner and outer frames before removing them. Do the complete job on one side at a time – allow two and a half to three hours for each side.
5. Make sure you can work comfortably, as well as safely, inside and particularly outside the boat; you will be spending some time doing careful work that needs a steady base.
6. To remove the old windows, drill out the rivets. Do this from the outside using a drill bit of about 6mm. The aim is to remove the flange so that the remainder can be gently punched through & out. If the rivets are heavily corroded into the windows, they may need to be completely drilled out. In that event, use a drill bit which is a clearance diameter for your fixings.
7. The old alloy frames become brittle with age so very carefully lever the window frame off by hand moving along the window in short stages. If you simply pull one end off the window and keep pulling, the lever arm will become too great and the frame will snap. The only option then left is to fit new, bronze windows. Very nice but very expensive; available from Churchouse Boats.
8. Clean off all the old sealants from inside and outside the cabin and from both inner and outer frames. Allow up to two hours for cleaning. You must get all traces of old sealant off and degrease the frames and cabin side before proceeding further.
9. My Drifter cabin has a lining which stayed attached to the inside face of the cabin.
10. Work on the frames on a thick soft pad; the frames are slightly curved and might break under pressure on a flat surface. Cleaning the frames will leave sharp edges, break them with a file; drill through the frame holes to clear them out and break the edges of the fixing holes with a countersink.
11. Refitting the windows is a two person activity. One inside the cabin – one outside. Your inside helper needs to give you about 15 minutes of their time. You will be applying sealer only to the cabin and to the parts already on the cabin. The inner frame, acrylic and outer frame will have no sealer on them when you fit them, one at a time.
12. Make a dry run following the instructions below to make sure all parts fit with the necessary clearance and that all fixings pass through their holes and can be tightened. Particularly check that the acrylic is clear of all the fixings. Ease the edges locally, if required. This is easily done with coarse abrasive paper or fine file. If the fixings clip the edge of the acrylic as they are installed & tightened, the glazing will crack.
13. Apply a continuous bead of sealer to the inside of the cabin where the inner frame will sit. Using four bolts as a guide offer up the inner frame and clamp it in place with your fixture. Check that remaining fixings will pass through their holes.
14. Move outside and fill the gap between the inner frame and the cabin opening with sealer. Then apply a bead of sealer to the cabin where the acrylic will sit. Remove the temporary protection film from the inside face of the acrylic and lay the acrylic in place. It will stay put because of the angle of the cabin side and the tackiness of the sealant. Remove the outer protection film.
15. Apply continuous beads of sealer to the outside of the cabin where the outer frame will sit, around each fixing hole and on the mating face of the acrylic. Fit the outer frame and fixings, in diagonal opposite pairs and finger tighten. Remove the four guide fixings and replace from the outside.
16. When all fixings are in place, finally tweak them up. They need to be tight enough to squeeze the silicon and hold all secure.
17. Once all is set and cured, very carefully cut off any surplus silicon that has oozed out. A scalpel-sharp knife is a good tool, carefully used. Whatever other method you employ, do not, under any circumstances, use acetone to remove surpluses. It will instantly cause your new acrylic to turn opaque.
These instructions include some common information from Stewart Brown’s
Churchouse Boats method
Steve Schlemmer
April 2005