Re: Stringer bedding compound, is thier an easier way
If you want super cheap, "bed" your stringers in foam. The pink stuff from the local home store is fine.
All the bedding does is keep the inflexible wood stringers from touching the flexible hull directly, which causes problems. What you want instead is for the force to be transferred to the stringers via the fiberglass tabbing and covering, which flexes at about the same rate as the hull.
You can actually "bed" stringers on air... leave a little gap using plastic spacers or similar. That misses out on the secondary function of the "bedding" which is to make a fillet for the glass to follow, so it doesn't form bubbles.
The cheapest way I know of to handle stringer installs is to position the new stringer on foam cut with a trapezoid cross section, like a little flat top pyramid. The top of the pyramid is the width of the stringer, the bottom a little wider. Hold the stringer in place on the foam with a jig or braces, double check the position, then glass over the foam/stringer/hull as normal. All done!
The bedding you're installing can be structural if it's made of something stiff with the same flexural modulus (bendiness) as the fiberglass, like putty made with resin. But if what you use is more flexible than the fiberglass then its only purpose is keeping the stringer off the hull until the glass is in place. PL falls in this category. It's too flexible to contribute anything to support.. by the time it starts to bend, the fiberglass has already taken all the force.
If you bed with something harder than the fiberglass, you're risking doing the same thing as laying the stringer against the hull, creating lots of hard spots.
Come to think of it, I suppose a good way to bed with air is to use plastic spacers to hold the stringer off the hull and in place, then tab it most of its length but leave a place to get the plastic spacers out. Then when it hardens pull the spacers, tab the last spots, then glass over the tabs as normal with more layers. Presto, no bedding required.
Of course, using nothing is harder than using foam, which is harder than just squirting some "glue" under the stringer...
Erik
