Fiberglass boats

[JohnnyTarr]

Ok I need help here. If I can't get help here please direct me to somewhere else. I am looking at repairing a very old and neglected Dolphin SR sailboat. I have to get the top and bottom molds apart. How would I do this without causeing more damage?

[Misson]

I recommend checking in with a local marine shop. When I was building the velociraptor prop (http://www.markck.com/images/props/PROPS_raptor.htm), I decided to make him fiberglass so he could remain outside (you have you lawn statuary, I have mine). The local marine ship knew all about fiberglass repair, sold me everything I needed and were very helpful, giving me loads of advice. I'm sure they'd be even better suited to advising you on boat repair.

[JohnnyTarr]

Yep that I am starting to do today. I am also going to try boat dealers. I hope to get somewhere with this before the snow falls.

[Morgan Dreadlocke]

Could ya be describin' the damage ye be tryin' ta repair?

[JohnnyTarr]

The damage is on the hull near the keel. It is a hole about 1"x2 1/2" with about a 6" crack leading aft from that. There is another crack in the cockpit about 8" long running from stem to stern. I have a few stress cracks that won't give me any problem after that is all fixed. I will also need to replace the sail, rigging, and rudder. I am looking at about $500 in damage.

[Morgan Dreadlocke]

Hmmm, sounds like the hull took a fall onta sumthin' sharp. If the hole be jagged with pieces of the old material still in it, could ye not saturate the area wi' resin, an pull the old pieces back inta rough alignment wi' a buttonhooked wire? Then scuff up the area over the hole an crack wi' 80 grit paper an laminate a 3-4" strip 'o glass cloth over the length 'o the repair. If ye be needin' pressure from the inside 'o the hull try deflatin' a kids pool ball an stuffin' it up through the hole. Inflate it just enough ta hold things where they be needed then glass the 'ell out of it. Yer local hobby shop might be stockin' a product called "Nomex". It be honeycombed glass in several thicknesses. Cut a piece longer than yer repair and as wide as can be pushed up throught the hole. Butter it up wi' resin, shove it up in there, then pull it back tight against the hull till the resin kicks. Yer cockpit problem might be from too little support under the cockpit floor. If the hull be all glass ya could shoot foam under the floor ta shore up all the flex. If there's any wood in the hull the foam will rot it out so be checkin' it out good before hand. I fears tryin' ta separate the hull from the deck would be akin ta tryin' ta patch a tyre by cuttin' the sidewall from the tread. Little hope of reassembly. Keep us posted an good luck wi' the project.

[Matusalem]

Hmm.

I didn't know why I woulda ever missed this one, today is 7/28/07. I worked as a boatbuilder for Shannon yachts and The Anchorage (Dyer boats) between 1987 and 1990.

I would say: first determine whether the deck and hull are connected through fiberglass & resin -or- by a caulking compound. If they are bonded together by resin, then I highly would suggest not separating the two halves unless you have a proper tool such as a 4-inch diameter diamond tipped blade, whcih I used to use at Shannon, and I suppose I could cut it but not very precisely. The blade would run horizontally down the flange. Pain in the ***.

If they are connected by a marine caulking, like SikaFlex, try a chisel & hammer and dousing the gap with acetone, then keep trying to separate them with the chisel & hammer, ad keep pouring in the acetone. Keep in mid that asolvent only works if the material you are trying to dissolve is made of a likewise chemical base (quoted from my step-grandfather who wis a retired chemistry professor at the US Naval Academy) .

The only other altenative I suggest is to cut a 5"x5" hole in the deck witha saber saw, save the piece, and do your work. You are doing patchwork, right? After you've done your great masterpiece of patchwork, whatever be the case, attach some small 3/4" inch strips 2" to the edge of the deck hole as amounting flange and epoxy the cut-out piece to those flange strips. Then fill the gaps with resin paste (resin with glas beads or glass fibers), which has the consisitency of toothpaste. Sand till flush with deck. Spray gelcoat. let dry then sand. Use an oscillating 4X4 sander start with 150-200-400 grit till you reach 1500 or 2000 if you like, then buff with compound and you will never know you cut a hole in the deck.

Hope this helps. Email me if you like.

[JohnnyTarr]

Ok I can find the stuff I need. It looks like I am not going to take the hull apart. It is resined together. I am still debating about trying to cut a access panel or do the work from the outside. I am a little confused as to what I am seeing in the hole. It seems that there are two layers one (the outside) is white and the other (the inside) is yellow and looks like a pattern of chicken wire on it. I am going to cut out the rough edges tomorrow and get a pen light into it and see what it all looks like. Keep a weather eye out for me.

[Matusalem]

It seems that there are two layers one (the outside) is white and the other (the inside) is yellow and looks like a pattern of chicken wire on it.

White: Gelcoat (enamel surface)

Yellow: Fiberglass roving (the cloth material impregnated with resin)

If you see real chicken wire, then it's a previous patch job.

All i can say is examine the situation from a hole in the deck.

You are best working from the inside, not the outside of the hull because you will never get the structural rigididy. Basically you need to get new fiberglass roving to overlap a hole about 6" to 12" depending on the size of the hole. Have 5" electric grinder handy, you will need it. make sure you lay your roving down with an air roller (basically looks like a paint roller but much smaller). You will need that when laying the fiberglass with resin. The air roller will remove air bubbles and give a structural bond to the hull. Air gaps will structurally weaken your patch job.