Fiberglass Question

D

Dave Fairfax

New member
I want to build a platform on the bow of my fiberglass boat. I am going
to frame with treated wood; doing the floor by screws and marine grade
adhesive. my question is when i fasten the framing to the gunnel how do
i attach it. i am afraid to use screws as they might breach the
outside of the boat. Not a problem with the floor because there is a
sub-floor, but the gunnels are much thinner.
 
What kind of boat? Can you post pictures? Seems kind of vague question.
 
I don't think you want to use treated wood. Although it sounds like a good idea, the chemicals in it are hard on everything and will likel make any metal and fiberglass fail sooner.

The frames should be glassed in.
 
Ok, thanks. I guess my remaining question is how do you attach the frame of whatever you are going to glass-in. By attach i mean how do you attach to the gunnels because they are so thin, unlike the bottom which has a sub-floor
 
If it is thin, put in a beefer strip of your choice on the inside to give more strength and distribute the pressure from the bolts, plywood, metal, etc.
 
Dave,
I 2nd the ... avoid treated wood. One, it's not Aluminum friendly and it's only use is truly in direct contact with ground (that activates the poison to prevent mold). Use marine ply.
Lou
 
Okay i think i have it figured with everyones input, please correct me if im wrong. frame it out with marine grade ply bolting from the outside the gunnels and in the subfloor. Use 3M 5200 or something similar to seal any where needing it (i.e outside bolts) then glass around. I know this is a very generic run-through but just wanted to make sure i am understanding the whole picture. Thanks everyone who has commented.

-Dave
 
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I want to build a platform on the bow of my fiberglass boat. ,,,,,,, my question is when i fasten the framing to the gunnel how do i attach it.
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Dave,

If you are dealing with a fiberglass hull it should be a simple matter to glass your framing directly to the glass of the hull. In other words, glue the new framing to the hull with epoxy resin and cloth in the same manner as stitch and glue construction. Fillet the joints and top with glass cloth, no bolts needed.
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As said before, do not use pressure treated wood,,,If you want to save a little money you can us Advantec,,,the stuff subfloors are made of these days,,,,I've put a couple of floors and transomes in boats using this stuff and had great success,,,,It's pretty much water proof and glass sticks to it with no problem,,,it is also strong as hell and the boards tend to be straight,,,,down side is it only comes in 3/4in and is really heavy, but it will make a very solid structure,,Besides having crazy chemicals in it,,pressure treated wood is very moist, if you glass over it your going to have delamination issues caused by all that moisture trapped under your glass, You can also save some money by using vinyl ester resin, it is considerably cheaper than epoxy,,,,not quite as totally awesome as epoxy, but very good,,,it is far superior to polyester in its secondary bonding characteristics,,,,,,by the way my period button doesn't work anymore,,,hence all the,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
 
thanks....very good information...i do worry about weight a little bit considering that i have not built the blind yet which will be the majority of the weight..but should still be under max capacity. i will definitely ditch the treated wood and used one of the various materials mentioned above. i also thought about putting a cubby hole/storage bin under the platform...something very small to keep a few things in....

any suggestions/comments would be great. especially on how or whether to glass the inside or not.
 
If your building a basic casting deck (which is what I assume your doing) then I think 3/4in wood would be appropriate,,,3/4" is sturdy enough by itself to support the weight of people walking around on it and will take the general abuse that occurs on a boat,,either marine grade plywood or the Advantec should work just fine (marine grade plywood being way lighter weight but more expensive) Using big wood lets you get away with using less glass,,,the glass can be more of a protective barrier over the structure instead of providing the majority of the structural support,,,As far as rather to glass the inside of the deck or not,,,,If you use smaller wood than 3/4 I think it will be necessary for structural support,,,,if you go 3/4 then I don't think you should have to,,,,I would however paint the inside of the structure (and all exposed parts that aren't glassed) with resin,,,,Do yourself a favor and paint the inside pieces before you install them,,,,,coating something with resin that is upside down is rather unpleasant,,,I would also suggest that you build all of your framing out of the 3/4 wood that your building the whole thing out of,,,,the marine grade or advantec is going to be a better choice to make a permanent part of your boat than pine or spruce 1x2's,,,,just cut 1x2's out of the sheets of plywood,,,and don't forget to sand/grind all of the gel coat and paint off of any area that you intend to glass to,,
 
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