Bog or Peel Ply?

I'm thinking one step ahead to laminating the first section of foam for the catamaran I'm building.

The lamination schedule is 1 layer of 34oz triaxial on 1" Corecell foam. That's it.

So, I'll be left with a rough surface, probably not even watertight, with pinholes.

What do I do to get rid of these pinholes and ensure the surface is both watertight and able to take the loads of a bulkhead which will be coved to it later on?

Do I use bog here, or peel ply? I have microballoons on hand, but very few yards of peel ply. I wasn't intending on using peel ply.

Which solution is best and why? What are the advantages and disadvantages to bog coating vs. peel ply coating when using only 1 layer of thick glass?

 

Is this inside or outside?

If outside, make sure you recess your overlaps into the foam, so you have only minimal fairing to do. Also fair your foam as good as possible.

After laminating, roll a film of epoxy over the laminate as soon as it has cured to a sticky/rubbery state. Do this twice. This will already leave you with a very nice result.

 

This is for both inside and outside. Replying on phone, so its short.

 

I,m told nylon fabric is cheeper than peel ply, and why not stick a 3 oz finish cloth over the triax filling the holes and providing smooth finished area for your bulkhead conections. rick

 

Inside I would peelply, leave the peelply on as long as practical. If you need to glue a bulkhead, run a knife lightly over the surface, (left and right of the bonding zone) and pull the peelply from that area only. This way your interior is protected from foot traffic, resin spills, etc. And bonding of bulkheads is good.

After big things have been done, pull the peelply, and coat with a durable epoxy coating, or scrape with bog first, then coat. Whatever you fancy. (I would just coat. It is a lightweight boat.)

 

Thanks, Herman and Rick.

Peel ply does sound good, so long as it's not terribly expensive. Rick, any sources (with no lead time and instant shipping) on the proper nylon? I have a small roll of peel ply and yes... it's nothing more than standard nylon fabric. Sounds all fancy, but it's not. I have a laundry bag and a jacket made of the same material.

Herman: So to peel ply the inside, what do I need to do differently? It's a hand lamination. Will I add two coats of excess resin, as you suggested earlier in the thread, then press down the peel ply? Is that the right way to go about it?

 

As a minimum use peel ply where you have structural bonding to do later on, also add your bulkhead backing laminates at this stage. All other surfaces you could fill the weave with bog if you like. But you already have heard my reasons for using it for all surfaces, both in and out.
You do not need extra resin in the laminate for peel ply, just allow 1:1 mass ratio for your glass + 200 - 300gsm to fill the foam surface (this depends on the foam surface finish).

Look for textile merchants or wholesalers in your phone book, you want a lightweight ~60gsm polyester tafata or nylon. With corcell best to use a light pastal coloured material so that you dont forget its there and laminate over it ( it has been done). Solid dark colours are not as good as you can not see trapped air underneath that well. Peel ply is not a fiberglassing specific material, its an adaptation. Most of it is used as a suit and garment lining material.

For final internal finish no need for extra resin seal coats in my opinion, only your balsa.

 

I can't even thank you enough, Andrew. I owe you about a brewery worth of VB's if I make it to Australia again.

Good advice, as always. I'll make sure to follow these instructions. I'm a little short on peel ply right now (but may find some in time). Good thinking to maybe use the peel ply only in the areas where the secondary bonding takes place for the moment.

I know you had said there is no need to seal bilge pin holes, but I do disagree with you on that one.

There is always going to be some wash of water (or worse, black water!) that finds its way into the bilge from time to time. I want to make sure my bilges are watertight and easy to clean. I've had enough head "explosions" in my years at sea to feel differently about this than you do. No worries though... thanks for all the help and advice.

 

I have purchased nylon from: http://www.hancockfabrics.com/Store-Locator_stcVVcatId541679VVviewcat.htm

 

The joys of peel ply are you can see all the hills and hollows and the wet glass is able to be semi faired with the roller press a little harder on the high patchs aand less on the lows . Can save you a lot of time filling and makes life a lot easyer . Its also a way of making sure you clothis 100% filled with resin to . On racing yachts where weight is save any where all surfaces are peel plyed an surplus resin comes to the surface and help to compress the fibres so when its riped off its a 100% clean surface and no resin sich areas .

 

Cat go to bateau forum , fiberglass paint, peel ply substistute. Evan Gatehouse posted, he is a designer for bateau, answers alot of questions on core material , fiberglass , building techs, ect. We get good advice on this forum,but one more source wont hurt, he has a website relateing to his boat and the live aboard cruising he his wife and daughter are doing.rick

 

Hoyt, was the nylon nice and clean... no contaminants?

If so, this is a great source, thanks! I can take a drive over that way in less time than I could have something shipped from far away.

Thanks!

 

I got my current small bit of peel ply from Joel over there at Bateau. Certainly agree... they know their stuff. Very trustworthy people to buy from too. I've had a good experience with the stuff I bought from them. Met Joel in person. Nice guy all around.

 

Makes sense. I guess I'll peel ply the whole thing. Less bog later and as Andrew says: Doesn't cost any more because you use less resin.

 

Hi Mr Hoytedow; when entering your kindly mentioned website for the purchase of a peel ply subtitute we find a place with literally thousands of fabrics made with nylon 2003 to be more precise .......... so maybe to be really helpful, you could tell us all which one exactly you have found to be a good substitute for peel ply