Refitting a Compass 47

[cpa]

We are using the standard epoxy resin from our local fiberglass coatings store (it is what they suggested). As for the fiberglass, I have more than a few yards of 17 oz biaxial cloth left over from a previous boat project. What do you think would be ideal an ideal cloth and layup on this project.

Also how do you feel about reusing the old skin? Is is worth the effort to lay new glass over the repair? Like I said earlier this area is one of two on the boat with a core and I want to never touch the cockpit core again.

[minaret]

Originally Posted by cpa

We are using the standard epoxy resin from our local fiberglass coatings store (it is what they suggested). As for the fiberglass, I have more than a few yards of 17 oz biaxial cloth left over from a previous boat project. What do you think would be ideal an ideal cloth and layup on this project.

Also how do you feel about reusing the old skin? Is is worth the effort to lay new glass over the repair? Like I said earlier this area is one of two on the boat with a core and I want to never touch the cockpit core again.

Brand? Biax will do fine for that. Personally I would use poly and glass the external skin with a 1708 sandwiched between two 1208 and both a start and finish matt. This gives a very strong 1/4" skin. Does yours have a stitch matt? I would not reuse the skin in an area that small. By the time you bond it down, grind the seam, tape it and fair it, it's more work than just pre grinding the edge, bonding the core in place, and glassing it all up with your layup tapering up onto the cockpit sides. Make sure your prep grind is substantial and allows for your laminate to taper properly without leaving a high. This is one of the most common mistakes I see from relatively new laminators, not enough grind. Will you bond the core in and do the layup with the same resin? Which hardener? Have you considered doing this in poly? Just questions to consider...

[cpa]

Originally Posted by minaret

Brand? Biax will do fine for that. Personally I would use poly and glass the external skin with a 1708 sandwiched between two 1208 and both a start and finish matt. This gives a very strong 1/4" skin. Does yours have a stitch matt? I would not reuse the skin in an area that small. By the time you bond it down, grind the seam, tape it and fair it, it's more work than just pre grinding the edge, bonding the core in place, and glassing it all up with your layup tapering up onto the cockpit sides. Make sure your prep grind is substantial and allows for your laminate to taper properly without leaving a high. This is one of the most common mistakes I see from relatively new laminators, not enough grind. Will you bond the core in and do the layup with the same resin? Which hardener? Have you considered doing this in poly? Just questions to consider...

Minaret,
Thank you for all of the help you have given to us on this project. Most of my professional "marine industry" experience is in the sail loft/rigger areas. I have never been shy of resin and glass, but with the guidance from you I feel like I am doing a better job than on past projects.

I plan on using epoxy as I have already purchased it and am more comfortable laminating with it. Initially, I was going to use poly for the gelcoat compatibility, but figured I have more experience with epoxy. The biaxial I have does not have stitch mat on it. Is there mat that can be used with epoxy (is that stitch mat)? I have read about binders that dissolve in poly when using mat, but not in epoxy. When using epoxy should I still use the 1208/1708 biax in the way you mentioned. The hardener I am using is the 3:1 stuff from Fiberglass Coatings. Here is a link:
http://www.fgci.com/pdf/..%5CMSDS%5C...0Activator.pdf


I also plan on bonding the core with the same resin I use to laminate the glass with. I will definitely work on a very good grind. What type of bevel should I shoot for? I have read between 6:1 and 12:1. I will take your advice and not reuse the skin.

My Coosa BW26 showed up today and wow that stuff is amazing. Way better than anything I was considering at Fiberglass Coatings.

As always thank you!

[minaret]

Originally Posted by cpa

Minaret,
Thank you for all of the help you have given to us on this project. Most of my professional "marine industry" experience is in the sail loft/rigger areas. I have never been shy of resin and glass, but with the guidance from you I feel like I am doing a better job than on past projects.

I plan on using epoxy as I have already purchased it and am more comfortable laminating with it. Initially, I was going to use poly for the gelcoat compatibility, but figured I have more experience with epoxy. The biaxial I have does not have stitch mat on it. Is there mat that can be used with epoxy (is that stitch mat)? I have read about binders that dissolve in poly when using mat, but not in epoxy. When using epoxy should I still use the 1208/1708 biax in the way you mentioned. The hardener I am using is the 3:1 stuff from Fiberglass Coatings. Here is a link:
http://www.fgci.com/pdf/..%5CMSDS%5C...0Activator.pdf


I also plan on bonding the core with the same resin I use to laminate the glass with. I will definitely work on a very good grind. What type of bevel should I shoot for? I have read between 6:1 and 12:1. I will take your advice and not reuse the skin.

My Coosa BW26 showed up today and wow that stuff is amazing. Way better than anything I was considering at Fiberglass Coatings.

As always thank you!

Anytime, always happy to help in any way possible!


Suggested poly because I thought you were finishing in gel. You still can if you tie coat with 545. Your biax without stitch matt (1700, the "08" is for the stitch matt) will be just fine for an epoxy layup. See if you can get a few yards of 1200 (1208 would be the same stuff with stitch matt) to go with it. I'd back grind this about 4", which for a 1/4" layup is 16:1. Then bond your core and flat stock in using 407 or equivalent, and fillet the edges with a fillet ball at the same time. Let cure and sand for prep. Clean and mask well for layup. I'd do a 1700 with three 1200 for this, cutting the 1700 so it only lays on the sole and doesn't have to make the bend up the sides. I might even go to two 1700 depending on how thick the original skin was. I'd taper the three 1200 up the sides on the 4" back grind, one each at 2",3",4". Unless the outer skin is too thin for that much grind and glass, then take it back to two. Cut all your glass, dry fit it and relief cut in place while dry. Then weigh it, and allow yourself an equal amount of resin for wet out. This will guarantee a lean layup. Use a slow hardener and do the whole layup at once. Consider peel ply. I often catch a chemical bond with a 407 slick for fairing instead, its much faster and better. Glove up well and don't forget your respirator, epoxy is bad news. Happy laminating!

[minaret]

The MSDS for your hardener doesn't help much. Is that Fast or Slow? I wouldn't do this layup with Fast.

[cpa]

Minaret,

Thanks again for the feedback and guidance!

The epoxy and hardener are the 3:1 at FBCI, here is a link to the product. It claims a pot life of 15 to 20 minutes:

http://www.fgci.com/bp_viewproduct.a...oldItem=125244

Do you think it would be worthwhile to to switch to a slower hardener? I could go 2:1 and have a 20 to 30 min pot life, but they say it will be less stiff/hard.

I hope to build the fiberglass stock tomorrow on my back porch. I will get a few pieces of Melamine mdf and see if I can find some woven roving and biaxial scrap pieces at the local Fiberglass Coatings store.

Lastly, I was looking on there website and noticed that they don't carry biaxial cloth without mat. Everything is 1208/1708 etc. Is there a possibility that they could have a 1208/1708 that is compatible with epoxy?

I have the next three days off and weather permitting I am hoping to get the core in and everything glassed up. I will try to get pictures up as I go.

[minaret]

Originally Posted by cpa

Minaret,

Thanks again for the feedback and guidance!

The epoxy and hardener are the 3:1 at FBCI, here is a link to the product. It claims a pot life of 15 to 20 minutes:

http://www.fgci.com/bp_viewproduct.a...oldItem=125244

Do you think it would be worthwhile to to switch to a slower hardener? I could go 2:1 and have a 20 to 30 min pot life, but they say it will be less stiff/hard.

I hope to build the fiberglass stock tomorrow on my back porch. I will get a few pieces of Melamine mdf and see if I can find some woven roving and biaxial scrap pieces at the local Fiberglass Coatings store.

Lastly, I was looking on there website and noticed that they don't carry biaxial cloth without mat. Everything is 1208/1708 etc. Is there a possibility that they could have a 1208/1708 that is compatible with epoxy?

I have the next three days off and weather permitting I am hoping to get the core in and everything glassed up. I will try to get pictures up as I go.

Totally unfamiliar with your resin system, but those are short pot life's. You will need more like an hour of working time. Obviously pot life and working time are not the same, the 30 min. pot life stuff might give you an hour of working time depending on temps. Use a slower hardener, do it early in the AM, or split it into two layups. Stitch matt will be OK as long as you always put it matt side down and never roll or squeegee on the matt as a result. Brush some resin onto a piece of cardboard or something at the intended temps and see how long it takes to kick, then you'll know how long you really have. Laying up flat stock will be good practice too. Good luck!

[SurfingMaverick]

Great thread and great tips found on this thread. I'm about to start with a refit of my own on my Atlantis 36, also a Lavranos design. I bought her little over a year ago, and first did a couple of races here at our local club, but when one thing started breaking after the other i realised it was time to stop playing and start working... You guys have a beautifull boat and did a great job on her!
Enjoy!

[cpa]

Originally Posted by SurfingMaverick

Great thread and great tips found on this thread. I'm about to start with a refit of my own on my Atlantis 36, also a Lavranos design. I bought her little over a year ago, and first did a couple of races here at our local club, but when one thing started breaking after the other i realised it was time to stop playing and start working... You guys have a beautifull boat and did a great job on her!
Enjoy!

Thanks! I love South African boats. The Atlantis 36 looks great. What type of work are you going to be doing?

[SurfingMaverick]

Pretty much similar work to what you've done. I need to paint the deck, and seal all the deck fittings that are leaking. The hull might need to be sprayed as well, hopefully i can get away with a good polish and wax job. The interior have little odd jobs, typical maintanace work. The plumbing is just plain scary.... The motor a Yanmar ym30 is still in good condition, i only have an issue with the prop, i think the pitch is not right... I'm only getting 4kn at 3000 rpm. Then i would like to make her a little more 'cruising ready', like add goalpost for solar panels and a bimini top. But otherwise i'm happy, she sails well and feels safe.

[cpa]

I guess it has been a while since last update. Work is going well, almost done with this part of the project. Just need to finish the floor and reinstall hardware. Here are some pictures.

[cpa]

After the floor was removed, we cleaned her up well and fitted the Coosa board with epoxy and a low density filler. Then we glassed it up with 12oz and 17oz biaxial cloth with epoxy. I have never considered myself a good person with glass, but I feel it came out pretty good. Coosa is amazing.

[cpa]

The sanding of the floor was almost too much fun. I felt like it was wintertime in RI when I was finished. There was at least a few inches of "snow" on the floor.

Then we sanded and faired the boat with 3M Premium Filler and did a final taping before the gel coat.

[cpa]

Next came the worst possible day in the project. We underestimated the amount of time it would take to brush on the gelcoat. more than 10 hours and 2 1/2 gallons of gelcoat later we were destroyed. We ended up brushing 5 coats and it was painful. NEXT TIME I WILL FIGURE OUT A WAY TO SPRAY.

Minaret, I should have listened.

[Exile]

Following your refit adventures with enthusiasm & interest!

Will you do a primer coat before applying your gelcoat? What about nonskid?