pulling a mold from wood

[Euro Scott]

anything special I should know before attempting this ? I'm making a new deck for a project boat and I've built the basic form from wood and too make the first copy that will be cut and fitted in several places for the final mold what should I cover the bare wood with ? I was thinking of spraying in gel and then waxing and pva'ing and then using a chop gun to spray in place.Im using my 21 shadow for a donor top and a wrecked 19ft STV euro for the donor bottom thats getting stretched from 19 ft to 22'6 and then widened between the sponsons to 8' from 6 ft 7" as well as changing the nose and the bottom as well as the obvious new top deck, I want to build it to accept a single outboard , twins, or one of my 540's merlins with a XR bravo. here's some pic's of my concept as well as the donor's..

[MOBILEMERCMAN]

I would think you need to build the plug tough enough to handle the pressures of curing glass. And finished smooth enough to use the piece with out more finishing work.

It seems to me the mold won't be of much use if the pieces built in it need finishing work.

[Steve 1]

We usually use Duratec primers, which can be sanded easy I take them to 1500 and a buffing (3M compounds) gives me a finish to mold off of.

Preparation a quickie for a one shot rough mold just resin coat the wood then prime and sand.

A plug that needs detail I always fiber glass it completely with at least a 1oz Mat tearing the edges for a consistent surface before starting any fairing and finish.. this hides a myriad of problems like joints and even screw heads that photograph through when the tooling gel coat sets (thermal issues and the styrene vapors) this saves any serious sanding on the mold which is the whole bag of marbles so to say.

[Perlmudder]

cool looking design, sorta like a mini mti!

[Offshore Ginger]

We usually use Duratec primers, which can be sanded easy I take them to 1500 and a buffing (3M compounds) gives me a finish to mold off of.

Preparation a quickie for a one shot rough mold just resin coat the wood then prime and sand.

A plug that needs detail I always fiber glass it completely with at least a 1oz Mat tearing the edges for a consistent surface before starting any fairing and finish.. this hides a myriad of problems like joints and even screw heads that photograph through when the tooling gel coat sets (thermal issues and the styrene vapors) this saves any serious sanding on the mold which is the whole bag of marbles so to say. i agree with Steve and just about every boat company i have ever worked for has used Duratec for all there tooling .

[Euro Scott]

sounds good, I appreciate the info..I got a deal on a used/ needs repair combo chopper/resin gun and pressure tank with mixing lines..bad news is it needs a new gun. its $350 to repair the seals and tank and $1,800 for a gun,dang, their real proud of that!! any suggstions on a used one somewhere its a binks 102-2455

[Steve 1]

sounds good, I appreciate the info..I got a deal on a used/ needs repair combo chopper/resin gun and pressure tank with mixing lines..bad news is it needs a new gun. its $350 to repair the seals and tank and $1,800 for a gun,dang, their real proud of that!! any suggstions on a used one somewhere its a binks 102-2455

Was the gun "setup" (hard resin inside) or just leaking also the chopper head does it work? these guns are easy to repair BTW IF you have all the parts.

[Offshore Ginger]

EURO SCOTT,i have a concern and that is ........... will the pannel board being as flexable as it is ........... be able to handle the weight of the chop , primer and the stress of tooling the part ( sanding ) and still be able to keep the shape that you desire ? Scott the board you are showing in your pics seem's a little weak for this sort of thing and have you considered using a stronger material and scoring it on the under side to achive all the compound curves you are l@@KING for?

[Euro Scott]

I wondered that too, I did built ribs underneith it and spaced them 12" apart as well as tied them together in 4 places(strigers). It pass'es the arm pressure test {calibrated} so we'll see, but as I first stated this is going to be cut in a few directions, some material removed and some sections added before the final mold is made,(basically it was something to work with which seemed better than nothing) timewise and had the basic measurements and shape...
As far as rebuilding the gun,they dont offer repair parts anymore for it..I guess I should just throw it out and buy new...lovely mentality.. It sure is shiny and looks good though..lol
Since that pic was taken,I have finished trimming the edge's and fastened it to the rib's,chanfered the sided of the canopy to more of a tear drop shape. I also had a brain frt and changed the tail to give it a duck tail (extending it past the transom) I have it covered and sealed and didnt take a new pic yet but will get back on it this weekend as my foam for molding the new nose on the bottom will be in tomorrow..