help with glass and resin quantities?

[chrishayes]

I am about to order all my supplies for my floor redo. I went and bought two sheets of 1/2" ACX ply last night and have the heater blowing on it. I have ripped the deck off, removed the motor and ordered all the replacement parts for it. Then this weekend I will be starting on removing the cap so I can get to the front deck portion and take a good look at the transom. I will still need to grind out whats left of the stringer.

Should I leave the bottom 1" or 2 to allow me a groove to help with the stringer replacement? You know, keeping them parallel to each other?

So, the boat is a 73 Wellcraft airslot 165, the motor is a 1974 merc o/b 1500. The boat is 16.5' long and I have not measured the width but I assume it is less than 50" and narrows down quite a bit at the bow due to the tri hull design.

How much FG and what weights do I need to purchase figuring that the transom is likely to need work as well(feels solid, still need to do cores when cap is off).

I am leaning towards Epoxy due to having less layup layers from what I have read and the inherent strength that it adds. Budget is not a huge concern because I only want to do this once and a few extra bucks arent going to be noticed a year from now, but the lifespan will. Make sense?

Is there a formula to figure out gallons of resins and FG for either using Poly or epoxy to allow me to compare the differences in cost and estimated time? I am terrible at math so it would need to be fairly simple...

ANy help would be much obliged. TIA.

Chris
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[danond]

Re: help with glass and resin quantities?

There's no need to have all your supplies before you start.

I'd suggest you order 2 gallons of epoxy resin, at least 10 yards of CSM (chopped strand mat or just "mat"), and 10 yards of 1708, sometimes called biaxial. That will get you going pretty well. Once you get into it and start using product, you can gauge how much more you'll need.

You don't want to overestimate with epoxy resin. It's $$$. Fiberglass isn't very expensive, so order a bunch.

 

[chrishayes]

Re: help with glass and resin quantities?

so am I right that if using epoxy I will only need one medium weight layer of glass on the deck and stringers? And will the epoxy work better for laying this over old glass without grinding the entire hull first? I would be more than happy to spend the money on epoxy if I can get away with one layer of glass and only a 6" strip of sanding before laying the glass on the old glass as an overlap/tab.

 

[chrishayes]

Re: help with glass and resin quantities?

ok guys, should have checked the sticky first. this takes care of quantities but the question still remains with regards to epoxies ability to reduce FG layers and its ability to be used over old glass.

 

[rucaradio]

Re: help with glass and resin quantities?

Where do you plan on ordering the resin and glass from? I'm a few weeks away from the same situation and am looking for a reliable online dealer with decent prices.

 

[92excel]

Re: help with glass and resin quantities?

http://www.uscomposites.com/ = reliable online dealer with decent prices

 

[92excel]

Re: help with glass and resin quantities?

so am I right that if using epoxy I will only need one medium weight layer of glass on the deck and stringers? And will the epoxy work better for laying this over old glass without grinding the entire hull first? I would be more than happy to spend the money on epoxy if I can get away with one layer of glass and only a 6" strip of sanding before laying the glass on the old glass as an overlap/tab.

Epoxy is stronger..
but epoxy or poly i would say two 1708 wraps is where you want to be..or equivilent which would be about 50 ozs give or take.

the deck you can get away with 8 - 10 oz. I suggest doing top and underside. adds waterproofing and rigidity.

i ordered 15 gallons of resin for an 18 foot boat and wont have too much extra. i also ordered 20 yrds of CSM, 15 yrds biax and 10 yrds of 8oz cloth.
i would say i was pretty close.. with a little extra.

 

[rucaradio]

Re: help with glass and resin quantities?

Maybe a dumb question, but is csm compatible with epoxy? The US Composites site has me confused about that.

 

[ondarvr]

Re: help with glass and resin quantities?

There's no need for CSM if you're using epoxy, but the prep work is the same for both resins...no short cuts on that part.

 

[Smeag]

Re: help with glass and resin quantities?

i ordered 15 gallons of resin for an 18 foot boat and wont have too much extra. i also ordered 20 yrds of CSM, 15 yrds biax and 10 yrds of 8oz cloth.
i would say i was pretty close.. with a little extra.

i thank you for posting that. i've looked everywhere on this site for approximates and really couldn't find an answer anywhere. i ordered 3 gallons to get me started and i'm doing an 18 foot boat. i guess i better get more on the way so i dont' get stuck while waiting for a delivery.

 

[PiratePast40]

Re: help with glass and resin quantities?

On my 18 footer with a closed bow, I'm right at 8 gallons for the transom, stringers, and coating the decking. Since mine is a simple layout with only 2 stringers, it's probably a ittle less resin that some of the others. I'm estimating another gallon for tabbing the deck at the hull and another to add the box bases under the gunnels.

Hope that gives you another number to help figure out what you might need. Another option is to check with a local boat repair shop and see if you can buy some supplies from them. There are some definate pitfalls with that approach but some advantages as well.

 

[ondarvr]

Re: help with glass and resin quantities?

To estimate the amount of resin needed for your project, measure the sq feet of glass needed to cover the stringers and transom and add up the weight of all the layers (10 oz cloth, 24 oz roving, 1.5 oz mat etc. mat is by the sq foot, the others are by the sq yard). Double the weight of mat for the resin needed with it, the other fabrics will use about 1.25 their weight in resin. When laminating over plywood you'll use a bit more to pre-coat the wood, plus you'll be wasting resin the first few times you mix some up until you get used to it, so get little extra.

 

[chrishayes]

Re: help with glass and resin quantities?

On my 18 footer with a closed bow, I'm right at 8 gallons for the transom, stringers, and coating the decking. Since mine is a simple layout with only 2 stringers, it's probably a ittle less resin that some of the others. I'm estimating another gallon for tabbing the deck at the hull and another to add the box bases under the gunnels.

Hope that gives you another number to help figure out what you might need. Another option is to check with a local boat repair shop and see if you can buy some supplies from them. There are some definate pitfalls with that approach but some advantages as well.

What are the pitfalls that you speak of? Just curious, I have been calling around town to see who has what. One of the guys I spoke with, I asked if he carried biaxial and he said "what are you using that for?". Curious if this is the type of "pitfall"?

I am hesitating ordering anything. I have read more than 80 hours so far and read through 10 different project posts from start to finish and hell i fell like I know John(Jsersca) oops, meadfisher. But, I still dont feel confortable ordering. I think I need to get over the hump. Problem is, everyone uses different methods... I wish there was a tied and true formula or at least a way to see the difference between 2 different methods say 15 years from now. Man, someone slap me, I feel like im standing on a waterfall looking at the water below. I just need to jump!

 

[ondarvr]

Re: help with glass and resin quantities?

Don't woory too much about about which products you choose to buy, your boat was made with mat and roving, for decades this was all that was used and the boats held up fine. Newer boats may use biax and/or other types of glass to save weight, but on a repair like this the weight savings won't be much. Just do your best to at least put as much glass back in as you took out, that's all that's really needed. If you don't order enough at first, you can easily order more.

 

[chrishayes]

Re: help with glass and resin quantities?

Don't woory too much about about which products you choose to buy, your boat was made with mat and roving, for decades this was all that was used and the boats held up fine. Newer boats may use biax and/or other types of glass to save weight, but on a repair like this the weight savings won't be much. Just do your best to at least put as much glass back in as you took out, that's all that's really needed. If you don't order enough at first, you can easily order more.

What are the pitfalls of buying local?

RVR you are truly an asset to this site.