Boat build from recently aqquired moulds

Hi all, Just signed up this morning so heres the story.

Ive aqquired a set of moulds off a well know auction site and will post photos up inside the next day or 2. There for a 14ft cathedrial hull with or without a cabin - essentially a CJR and i would like opinions on the build as i propose to do it.

Plan for hull is:

1. 1 coat of gel via brush
2. 2nd coat of gell via roller
3. 1 layer of 450 cs
4. 1 layer of 600 cs
5. 1 layer of 600 woven
6. 1 final layer of 450 cs
7. 1 additional strip of woven along chines & keel

now for a few questions

1. Would i need as much of a build up on the ring mould/cabin?
2. Would a 1.5" (2 x 3/4" ply) build up of a transome suffice (40hp max)?
3. At what point would ou reccomend to fit the ply? Build hull up as above and then glass ply in (if so would 2 layers on top do?)? Or glass it in perhaps before the 600 woven layer?
4. For the join between the hull & deck/cabin im planning on bonding together with a bonding paste and then 2 layers of 450 internally over the joint. Would this be OK?

Thinks thats enough for now. Thanks in advance.

James

 

QUOTE=hardguy007;565410
Hi all, Just signed up this morning so heres the story.

Ive aqquired a set of moulds off a well know auction site and will post photos up inside the next day or 2. There for a 14ft cathedrial hull with or without a cabin - essentially a CJR and i would like opinions on the build as i propose to do it.

Plan for hull is:

1. 1 coat of gel via brush
2. 2nd coat of gell via roller(add about 20 % resin with you second coat makes it a lot easyer to roll out Use 2% catalyst with alll second coating gel coats )
3. 1 layer of 450 cs
4. 1 layer of 600 cs( this i would substute with 2 x 450 csm )
5. 1 layer of 600 woven (change to 800gram wr)
6. 1 final layer of 450 cs
7. 1 additional strip of woven along chines & keel( 2 strips with a csm between and 1 more to cover
All chines and the keel is the place where all glass get over lapped a minimum of 200 mm (100 a side)
Same with chines lap 100 mm up the side and 100 mm topsides down over the chine /bottom
now for a few questions

1. Would i need as much of a build up on the ring mould/cabin?
2. Would a 1.5" (2 x 3/4" ply) build up of a transome suffice (40hp max)?( yes all way across and a additional layer inthe centre 500mm wide where the outboard fits and gets clamped to or bolted !! power trim or not ??)
3. At what point would ou reccomend to fit the ply? Build hull up as above and then glass ply in (if so would 2 layers on top do?)? Or glass it in perhaps before the 600 woven layer?(yes fit the transone at this point with 2 x 450 scm under and clamp so resin comes out !! Drill lots 3/16 bleed holes all over the transom so dont get air pockets between . 2x 450 completely over and a 200mm wide strip w/r all round the transom to the hull . sounds like over kill but nothing worse than having a transom that flex's and moves !!
4. For the join between the hull & deck/cabin im planning on bonding together with a bonding paste and then 2 layers of 450 internally over the joint. Would this be OK?
hope you can read all this !

Thinks thats enough for now. Thanks in advance.

James

 

That all makes sence, cheers. As the moulds have had quite a few out of them whats would you recommend for release agent? Wax? Wax and pva?

 

If the moulds are good and clean then 4 coats of wax should be ok leave a couple of hours between coats . Use a dampbut well wrung out sponge to apply the wax and lightly polish of after about 5 minutes dont rub hard you need to leave as much wax on as possible !!!!

 

How progress??

Hi
So your from Ireland then are ya ??
Hows everything going ?? make sense of everything ??

 

Yep, from causeway coast in n. ireland. Moulds haven't been believed yet but im pretty happy with what I have to do however actually doing it could tell a different storey.

 

wow a beautiful part of the world and interesting !!
good luck !

 

Me again...was wondering if it's ok to keep laying up or is it better to lay 1 or 2 layers and
let cure before continuing.

 

You have to work within your gel time !!

2 layers of 450 csm is ok even 3 if you can work with that much glass at one time .
a woven plus a csm 450 is not a problem !. its all to do with the time it takes for the resin to gel and the amount of warmth the gel 'd resin will produce as it hardens and cures .
Just warm to the touch is ok !!
very warm is a worry !!!
and hot is not good at all !!
once it cools will shrink !!!
Life revolves around the catalyst ratio you use and the gel time of your resin. check what is recommended for the resin and that should be what you use !.
Catalyst can range up or down a little but there is a upper and lower limit that you can work within and dont exceed !!

 

Finally got the moulds some did and overall ther in good condition apart from a couple of chips due to transport.

So......

What's the best way to repair chips ( finger nail size)?

There are a couple of the corners were there are the hairline birds feet shaped cracks. How's the best way to sort?

 

Ok first are you able to post photos here on this sight ??This could help greatly as you go along !!
The birds feet cracks are usually called star cracks . most common cause id the mould would have been hit from the outside and makes the gel coat crack inside . These start cracks in bad cases can be right through the gelcoat and into the glass layer/s below . only way to get rid of them perminantly is to grind them out and replace the damaged glass and then re-gelcoat and sand and repolish back to the origanal size shape and finish .
the chips just need a touch with a grinder to take away the sharp edge and give a edge that is able to be feathered out , if the old chip is still there simply mix a little resin and lift the chip and get enought resin under it so when you push down its squashes out from under and completely fills the very edges . OR if the chip is missing touch with a grinder and get it 100 clean and fill with gelcoat and let go hard . The gelcoat about 1 tea spoon quantity needs just 1 drop of catalyst and can use a match stick or tooth pick and make sure its 100% mixed properly!! Is best to use one drop of liquid styrene wax as well also mixed with the gel coat so the gel goes completely hard on the surface and is not sticky . Always over fill slightly above the moulds surface as gelcoat shrinks back about 6% as it hardens . Always use a wooden block with all your sand papers ,and be gental !!
Gel coat needs 1.5% catalyst so mixing in small quantities is very easy to get a far higher ratio than close to the 1.5 % !!, be-careful !!
To much catalyst it will kill the gel coat !! to little and it stays soft and will never go hard properly and is almost inpossible to get a shine on again !. .