1974 19-6 Restoration

[Capt. Bob]

JF, you're in the catbird seat here.
You are doing a complete deck replacement. You can craft the hatch size to whatever you desire.

As stated, the tools and talent are scattered throughout this Forum.
You're on a roll, hard part will be picking a color.  

[gran398]

Looking at $500-$600 for similar size hatch at first 2 websites I found

    Then why not scavenge the skeleton (both lid and frame) of your existing hatch?

^^^^^^^

Excellent!

[jfret]

As stated, the tools and talent are scattered throughout this Forum.

Capt. Bob.....right you are....just read the thread from Kaptain Koz on hatch mold fabrication....incredible.

[jfret]

just to follow-up to gran398...I had tossed the old hatch....it didn't have any type of frame. It was screwed down to a lip around the hatch opening. I've never made a hatch but I was pretty sure that I could do a better job so......hope I don't eat those words

[gran398]

All good!! Koz is the man, and has done us (and others on the net) a great favor in his documentation

[kaptainkoz]

My ears were ringing... I thought it was tinnitus but im glad its not! Thanks for the kind words. A tank cover is just a larger version of the door that I made for the hatch. The hardest part should be matching the rounded corners but once you have a mold made the layup is easy. You would have to take into consideration if you are using gel coat or paint. If you are going to paint it then you have to make the mold a fraction of an inch smaller to accommodate the paint after. Gel coat can will pop out the exact size.
I always start with 3/4 oz chopped strand as you want the thinnest glass to conform and marry to the shape of the mold. Fiberglass naturally does not want to bend and does not like right angles so start with the thinnest layer first. Then I would use a layer of 1.5 oz chopped strand. After that you can go with many more layers of 1.5 oz or graduate to 1708 biaxial for fast build. I would think that 3/4 + 1.5 + 1708 + 1708 (about 36 oz of glass) should be enough for a stout shell.
Next is the coring. You can use traditional plywood which is tried and true. You can use synthetic coring like Coosa board or Carbon Core which is pricy and has distinct pluses and minuses, Or you can use Sea Cast self leveling mix which I haven't used myself yet but I am going to core my existing gas tank cover with it. You basically mix the stuff up, pour it in, come back tomorrow and its done. You do have to add a final layer of glass to either the plywood, synthetic coring or the seacast and I would use no less than the 1708 for that. Think of a surfboard, the strength is in the entire assembly of glass, coring, glass. Same thing with the gas tank covers. Also if you use plywood you want to encapsulate it from the elements which that last layer accomplishes.
Resins can be either polyester resin which the whole boat is made of, is the cheapest and most readily available. Or you can go with my favorite, vinylester resin which is (unnecessarily) stronger but more expensive per gallon. Last is epoxy resin which is strongest, most expensive and follows a different set of rules as you cant use chopped strand fiberglass with it because it does not contain styrene which is what breaks down the glue holding the strands together. You also cannot use gel coat on epoxy. Im not a fan of it nor do I have any experience with it. Vinyl or poly is all I am used to.
Lastly consider the thickness of the door. How deep is the frame that the door will sit in. You can make the mounting edge the exact thickness you need to keep the cover flush with the surrounding floor and then have the remainder of the surface thicker for support. For example, lets say you only have 3/4 of an inch depth to the frame. Obviously you could not use 3/4 plywood as the fiberglass could take 1/8 to 3/16th of an inch. You can always use a 3/4 slab but router the edge down so the edge thickness will allow the door to lay flush but then belly to full thickness where it isn't sitting on the lip to keep the door stronger. There are many ways to do it and make it look and work great.

Sorry if I am rambing stuff you may already know but I was on a roll. My hatch frame was the first mold I ever made, the doors to them was the 3rd mold I ever made. I am no expert, If I can do it anyone can. Let me know if you need anything further I am happy to share what I know.

[jfret]

Thanks to all for the advice and time spent sharing your knowledge..the learning curve is STEEP  indeed. :shaking:  The sheer volume of product and information out there is overwhelming. I think I've finely got a good enough grasp on the process to get started......thanks to Classic Aquasport and its members.  

[kaptainkoz]

We are happy to help you out. I started out knowing nothing about my boat and thanks to this site and the people on it, I have attempted things I would not have done without the great guidance found here. I pay it forward as gratitude for what I have learned here. Keep up the good work and post pics.... We love pics!!!!

[jfret]

Well I have finally finished most of the repair work on the hull and keel issues as well as replacing the existing drains with 2" PVC. I chose to make all repairs so far with epoxy......after many hours of surface prep I applied 2 coats of neat epoxy so it could flow into the nooks and crannies. I decided to take the advice of Aquasport Commodore and go with the Prisma products. I'm going to put the 1708 on when I finish foaming the stringers.

That looks like woven on the keel stringer. If it was me, I would take the middle stringer out and replace with the Prisma stringer system http://www.jamestowndistributors.com/us ... +Stiffener. The put 1 layer of 1708 over the entire length to cover the joints and call it done. Maybe put 4 of these down the middle for stiffness http://www.jamestowndistributors.com/us ... ull+Planks Wont have to worry about it any longer. Just wet and stick. Your looking good and sound like you have a great plan going

Before


After



There was nothing separating the stringer structure from the bilge drains.....





Right or Wrong......2" Drains installed....



Hull Stiffeners and Keel repair complete.....





Next thing is foaming the stringers....have found this to be pricey as well. Looks like about 350 for 20 cubic ft of 4lb 2 part.... :santa:

[Aquasport Commodore]

Looking good. Are those the 4" ones? Suggestion, you might want to make a small pad out of left over epoxy and cabisol or chop strand fibers and pour into a form. Let harden and remove. Attach to the bilge area with epoxy and then use as a pad to screw in bilge float switch and bilge pump. Similar as to this stuff http://www.jamestowndistributors.com/us ... lass+Board. It won't rot, hold the screw and not compromise the hull bottom.   As for the foam, see if a local boat builder will give you a price on just spraying in the foam for you and you do the rest. Might be cheaper or just the same amount as you doing it yourself.

[RickK]

Looking real nice     The drains are a nice addition.
Another point of view is that I am not sure you need the 4lb foam as the stringers are the structural part - think about using the 2Lb version. You can stabilize the stringers by putting a strip of cloth from side to side over the top every couple feet (maybe with poly) to keep them from deforming.  You can save some bucks  
That's what I would do and is what I did on mine.

[jfret]

Thanks for the compliments and advice....Yes they are the 4" stiffeners, they were not expensive but they sucked up the epoxy :pig: ....I read through numerous forums on "structural foam and stringers" but all I could find was conflicting information......using 2lb foam will save quite a bit of money...nice. What are your thoughts on pouring the foam? Should I enclose the stringers and leave a few access holes or is there another way?

[Aquasport Commodore]

If you are going the pour method, put into the open stringers. Cut the top level at the desired height. Round over the edges and reglass. Much easier then trying to pour into a hold and having voids.

As for the 2lb here is what Us Composites says http://www.uscomposites.com/foam.html

Common Applications: Our 2LB density marine foam is recommended for void filling in nonstructural applications. This product can be poured underneath decks and inside cavities where a lightweight flotation foam is needed to provide buoyancy. This foam has been tested in accordance with U.S. Coast Guard Regulation # 33 CFR 183.114 . This foam is approximately 95-98% closed cell which resists absorbing water, however continuous water submersion can eventually lead to loss of buoyancy over a period of years. We recommend this product strictly for flotation applications. If looking for a liquid foam for sculpting or casting we recommend using at minimum our 3LB or 4LB density.

Here is the 4lb

Common Applications: This 4LB density foam is suited well for most flotation applications that require more support than the 2LB offers. This foam is recommended to be used when supporting gas tanks and some deck areas. Choose this density if you feel that the foam will be required to withstand minor to moderate loads. The 4LB density also works well in floating decoy or taxidermy applications as well as many other sculpting, casting, carving and other filling applications

[CLM65]

While Rick's recommendation is probably fine, especially if you plan on putting foam between the stringers for flotation, I personally would (and did) use 4# foam.  While many will argue that the stringer foam is not structural, I know the foam did make a tremendous difference in the strength of my stringers.  On my flatback, the stringer glass was pretty thin and quite flexible with the foam removed.  After filling them with 4# foam, I can stand on them with zero flex and zero compression - they are rock solid.  By comparison, I filled the center stringer in the bow with 2# foam (I am one of the few that left that stringer there - most removed it).  This stringer is a little bit "spongy" feeling compared to the others.  Granted, I probably have more glass on the main stringers than the front stringer, but the main stringers will be supporting quite a bit of weight, so I wouldn't skimp on the filler.

On the other hand, if your stringers are as robust as Rick's, you probably dont need any foam at all  

[jfret]

Thanks for the input......I'm guessing this topic has been discussed before and I can see why...... Are the stringers themselves the structural component with the 2lb foam primarily providing floatation, or do the stringers depend on the 4lb foam for additional structure. Is the density of the original foam known? The stringers in my boat are pretty stout...if they were closed in with 1708 I don't believe they would flex at all but I really don't have any idea of the stress they would be under in heavy swells. I also have a question for the Moderator(s). I am looking at buying a trailer and boat (not an Aquasport) for the motor, trailer, and salvage parts. I'd like member input on this. Should I post as new topic or continue in this forum. Thanks :|