22' Young Boat Restore Help

Par,
Don't yell at me, I'm a virgin epoxy laminator with virgin ears!
All kidding aside, Boat Builder Central and Us Composite both recommend I use 1708 to build up the outside and inside skin to original 1/4" thickness. (4-6 layers)
I modeled my transom restore on the results from two posts on Bateau.com Boat Repair and Rebuilt Support: (Sorry I don't remember how to create the hyperlink)
Aquasport Rebuild -Classic "Flatback" by Shine
1981 Mako 17 Project by gw204
My plan is to attach the melamine dam to the transom's remaining flange. The inside surface has been ground to a taper.
First layer against the melamine is either 6 or 10 oz. cloth that will fit inside, covering the flange but not wrapping the sides or bottom.
Second layer is 1808 that is cut to fit and fill the recess cavity between the flanges. Trying to level out the inside surface.
Third layer 1708 cut and fit to the inside, covering the flanges but not wrapping the sides and bottom.
Next put a fillet in the corners.
Fourth layer DB1700 covers and warps sides and bottom by 6"
Fifth layer DB1700 same but 12"
Next glue in core 3/4",1/2", 3/4" fill in the gaps between it and the hull.
Fillet and tab with 12 oz. biaxial tape.
1808 fit inside but not wrapping.
1708 fit inside and wrap 4"
Two more layers of Db1700 wrapping 6" and 8"
The material I have on hand enough for:
Two layers of 6 and 10 oz. of fiberglass cloth
Two layers of 1808
Four layers of 1708
Four layers of DB1700
What do you think?
Also are four coats of release wax on the melamine enough? Should I also apply PVA?

 

Well, considering you'll probably buy resin from them also, it would be a reasonable business decision on their part, to insure you use 3 times as much as necessary, by suggesting combo fabrics.

You don't need the same thickness of skin with if using knitted fabrics (biax) and epoxy, as you do with CSM and polyester resin, to develop the same strength and stiffness. In short, you can achieve the same strength and stiffness with half the thickness, using straight biax, no mat and epoxy. As a side benefit to this, you'll use 1/3 as much resin too.

No one is yelling, I just thought I was clear about using biax and not any mat with epoxy laminates.

 

Par,
As I said, I was only kidding and appreciate all your help.
That's what I thought about the suppliers suggestion and ordered the 17 oz. biaxial.
Should I eliminate the 1808 layer and buy some more DB1700?
How many layers do you suggest?

Also what is your opinion on the release wax and PVA?

 

1808 is 18 ounce biax fabric with an 8 ounce mat knitted to it, so yep, eliminate it too.

I don't have much need for release wax or PVA style release agents. When I do have a need, I fall back on plain old automotive paste wax. A few coats of this and you're good to go, usually for a lot less too. In most cases I find I can use a "film" rather then a release agent. Mylar and clear packaging tape are very commonly used, both will shed epoxy, like a good looking woman does with my attention.

 

The transom came out very well. Thanks all for the help.
I need some claification on fairing?
Epoxy fairing compound (QuickFair) can I apply it over paint?
Do I need to cover it with epoxy after final sanding?
The hull is painted with at least two colors, its not pealing.
I plan on using Interlux paint either Perfection or Brightside.

 

Yes, you can apply fairing compound over paint, but and it's a big but, it's adhesion is purely dependent on how well "stuck" the paint is, which isn't good usually.

Generally, we fair over resin or other fairing/smoothing compounds. This permits the best adhesion. Yes, it's wise to seal the fairing compound with a coat or two of straight epoxy, before priming for paint.

BrightSide will give you a great finish at a fraction of the cost of Perfection and it's a lot easier to apply too.

 

Would I be better off stripping the paint off the hull sides?
Interstrip 299E states it strips paint off all surfaces including fiberglass?
What's your opinion of this method?
I also have to remove all the paint on the bottom and I was going to try a stripping product first before sanding.

 

The only time you actually need to remove paint is if you have to get at the actual surface. Typically this would be for repairs, bonding, modifications, etc. Paint can be smoothed, blocked to fair with building primers then repainted to a flawless condition, without taking it back to raw wood or the original surface.

Painting is all about the surface prep. If you spend the time on surface prep, you'll have a killer paint job. So, don't make more work for yourself then necessary. If you have to remove paint because it's peeling, damaged or other wise needs it, that's one thing, but removing well attached paint just because you can is just extra work.

 

I'm installing two 30 gal. aluminum gas tanks below the deck.
I have built up the stringers to the deck using two 3/4" ply. and warpped the area with 17 oz. biaxial
The tanks are to sit on` two 1/4" x 2" x 48" strips running for and aft. They will be bolted to the raised stringers three bolts each side.
The question, do I have to add bulkheads to close in the compartment?
The area below the deck is all open.
I've installed one bilge pump forward and a washdown pump and bilge pump aft.