Fiberglass boats that go offshore in the Captain's eye's should have at least four water tight Bulkheads.Fiberglass boats that go offshore in the Captain's eye's should have at least four water tight Bulkheads.
A collision bulkhead forward in the bow section. This compartment is used as a anchor rope storage compartment. If the boat is engaged in a head-on collision and the collision bulkhead doesn't fail your still afloat! A bulkhead forward of the main engine and bulkhead aft of the main make up for the engine compartment. Stuffing boxes for shafts through hull fittings below the water line are contained here. Hopefully, if they leak or the fiberglass boat hull gets breached below the water line, the water will be contained in the engine room. The bulkhead act's as a sound barrier and heat barrier and fire barrier as well.
Aft to the stern, another bulkhead makes up the Lazarette were the rudders are. Dropping a rudder offshore is a traumatic experience even for a well seasoned old salt! Bottom line survivability, matey. Pay action to your fiberglass boat bulkhead!
Boat Bulkheads are constantly under attack. As the fiberglass boat hull runs through a sea, flexing and vibration occur stressing the bulkhead. Moisture in the bilge add to the problem. Heat from main engines, generators and vibration add to the stress. Bulkheads are structural members of the fiberglass boat hull adding the transverse strength to the boat hull and reduces flexing.
Prior to the late ninety's most fiberglass boat builders used marine plywood for bulkheads. Laminated to the fiberglass boat hull with polyester resin and fiberglass mat and fiberglass woven roving 24 oz. This process is known as taping-in or tabbing. Done correctly, the eight to twelve inch strips of fiberglass mat and fiberglass woven roving are wetted out with polyester resin laminated to the fiberglass boat hull and to the marine plywood bulkhead, making a strong connection. Over time and use it's not uncommon to find the fiberglass de-laminate away from the plywood bulkhead or the plywood degrading. A close inspection will tell the tale. The 1977 thirty five foot solid fiberglass Bruno/Stillman Sport Fishermen came to Captain Levi for bulkhead replacement in two thousand and three. Twenty Five years of time and offshore waters broke two of her bulkheads lose. The integrity of the marine plywood was gone.
Above Roni is trimming down one of the new boat bulkhead. The new boat bulkhead is a full 2" thick. Built out of two 3/4" marine plywood laminated together 1.5 oz Fiberglass Mat Fabric. Fiberglass Materials Catalog #FGM-1.5 oz and 1708 fiberglass biaxal Fabric fiberglass Materials catalog #BX1708 on both exterior surfaces. This type of fiberglass construction is over 3 times the strength of the factory boat construction. The white looking material along the edges of the bulkhead is ARJAY 2001 by ARJAY PERFORMANCE PRODUCTS Fiberglass Materials Catalog #ARJ-BP, a general purpose polyester bonding and filling material that we stock in are store and ship Nationwide. This provides high strength bond between the fiberglass laminate and the plywood.When we bed the bulkhead in ARJAY 2001 we put a 4" radius were the two types of material meet giving extra strength to the fiberglass material tabbing.
Above Clarice is getting ready to tab in the new boat bulkhead. The fiberglass material in Clarice's hands is 1708 Biaxle fiberglass Fabric very high strength fiberglass material. Clarice will laminate 1 12" wide then a 14" wide finishing with a 16" wide laminate that will make a tapered finish fiberglass laminate, are choice of Polyester Resin for this job is are GP-200.
GP-200 General Purpose Polyester Resin is are most popular Polyester Resin. A favorite of Fiberglass Boat Builders and Fiberglass Boat Repair Shops Nation Wide. Most fiberglass boat and yacht builders use General purpose Polyester Resin. GP-200 is a room temperature curing, rigid, translucent, polyester resin for use with fiberglass fabric. It is an air-inhibited resin so additional layers can be applied without sanding between laminates. Consequently, GP-200 is often called bonding resin or laminating resin. It is an air-inhibited resin so additional layers can be applied without sanding between layers. Consequently, G-P 200 is often called bonding resin or laminating resin. Successful applications include boat-building, auto body construction, mother mold production and other reinforced plastic parts by hand lay-up or chopper gun.
Above you can see the aft engine room fiberglass boat bulkhead is tabbed in. Clarice is laying out the lazaret bulkhead fiberglass tabing material. Clarice uses heavy duty bent trimmers 10" and 12" shears that are perfect for cutting the fiberglass fabric Fiberglass Materials Catalog #SCI--10 and SCI-12. For Kevlar Clarice uses 10" specially designed shears with serrated blades to cleanly cut Kevlar Fiberglass Materials Catalog #SCI-KEV.Clarice is very personal about her shears not even the Captain can use them!
ABOVE Ronie is applying Arjay 2001 a general purpose polyester bonding and filling material to and old structural member that supported the inner liner aft deck. We are raising the aft deck 8" higher than originally designed which well make the Bruno/Stilliam more sea worthy her cockpit was just to deep. Leaving the old structural member will add strength to the boat transom. Arjay Performance Products.