How-to Article ...by Eddy Barnes
Step-by-step instruction on installing engine rails in a hull...
1. We at Offshore Models install the engine rails in our hulls when the glass is still wet and still in the mold. When we lay up our hulls we place the engine rails in and glass in as soon as the hull dries, but you might not have this luxury. The following is the method we use when installing engine rails in a hull that is fully cured, or in a used hull requiring engine rail replacement. It is always a good idea to sand the surface where the engine rails are going to be installed because some resins form a sealed surface. Different resins are used in hull building and this may vary from one manufacturer to another. Some resins contain wax and this wax has to be removed from the surface to allow the new resin to adhere. It is good to wipe down with acetone, the area of the hull where engine rails will be installed, to remove oil or wax.
2. When cutting out 2 wood engine rails we suggest using 5 ply 1/4" thick aircraft grade plywood, available at most hobby stores. We found that engine rails 2 ½" high by 24" long will fit most applications. Make a small 45 degree angle cut in the engine rails at the bottom rear corner where it meets the transom. This will allow water to pass between engine rails and transom, thus preventing it form being trapped in the hull. Another good piece of advice is to taper the front upper part of the engine rails to fit under the deck. This makes it easier to get things up and under the deck like flotation.
3. If possible try to make
a pair of holders to help you set your engine rails in place at the desired
placement of 5, 5 1/2 or 6" whatever you need. Remember to measure the inside of
the rails, not the outside. For instance 5" engine rails would measure 5"
between the rails and 51/2" outside of the rails using 1/4" engine
rails.
4. The engine rails now need to be put in place,
center the rails and push them all the way against the
transom. A good heavy bead of hot glue on both sides of the engine
rails will hold them firmly in place. After the hot glue sets up remove the
holders. The rails should stand up right and be firm enough to work
on.
5. Cut 4 strips of mat the
length of the engine rails. The strips of glass should be about 2 ½" wide. Wet
out the strips of mat one at a time, make sure they are fully saturated. A small
paintbrush can be used for this. If you let the strips soak to long they will be
harder to work with, so it is better to get them wet and install them as quickly
as possible.
6. Wet out the area of the engine rails where the
glass strips will be installed. Cover the wood and
sanded part of hull completely.
7. Place the saturated
strips of mat into place in the hull. Lengthwise, half should be on the hull and
the other half on the engine rail so as to join the engine rail to the hull.
8. Push the mat into the area and work the air bubbles out with you fingers and a paintbrush. Dabbing is better than brushing because you don't want to pull the mat out of place.
Work the
air out by dabbing with your paintbrush and remove any excess resin, wiping off
the exces
s on the side of the resin cup. You will have to watch
the mat for a little while to make sure that it doesn't lift. Once the resin
starts to cure you are home free. Let everything cure completely and start
setting up your boat with brand new engine rails!
ed. Marc Levac