Awlgrip great stuff ... but for beach cats?

[Roughrider24]

Hi... I'm new to the forum, and finding superior information posted here at boatdesign.net compared to some of the other forum sites, and thus my decision to join in here.

I've recently bought a beach catamaran (Nacra 5.2) as a project. The hulls are both pretty solid, but they need paint ... or re-gelcoat application on both tops and bottoms. (Sun damage on top and shore abrasion on the bottom). I continually read that re-gelcoat is painfully work intensive (sanding orange-peal and then buffing) and that Awlgrip (and similar two part paints) are a much quicker and potentially a better appearance solution with good long-term durability. But, I also read that Awlgrip is pirmarily for above water applications. Beach cats however typically get drug on the beach sand and on shore rocks in area lakes, and so I question if Awlgrip (or other like paint products) are a viable solution for me. Another possible concept could be spraying Awlgrip on the hull tops and sides and then a sacrificial layer of Marine-Tex epoxy putty (or the like) on the bottoms. The thin topside paint and thick expoxy bottom could possibly represent a lighter weight and more durable solution as well, but I think it could be a bit tricky for me to smoothly transition from one coating to the other. Anyone have any experience or thoughts to share on gel coat vs paint on boats that regularly get drug on the beach? I'm sure thinking Gel-coat may be the right path for this application.

Many Thanks!

Awlgrip is put under the waterline all of the time.
Gelcoat application is not as difficult as people make it out to be - spray (even roll), wet sand, buff - perfection is the difficult part.
Epoxy is tougher.
This stuff (K5) is http://www.specialty-products.com/po...high-strength/ is something to look into.

[Chris Ostlind]

At this point in the boat's life, (a 5.2 isn't exactly a new boat) it would be my preference to go with paint. It's easier to apply, costs much less (especially if you get an alternate paint to Awlgrip) and can be touched-up simply and quickly. Gell coat will add more weight to an already weight sensitive boat.

For day boats, such as a beach cat, you can give a long look at a really good, oil-based porch and floor enamel that has a urethane additive for hardness.

A solution for the bottom that sees lots of possible abrasion on rocks, heavy shell chunks, etc., is to go with a graphite powder mix with epoxy and give the hulls a couple of coats. The boat will slide easily over gravel and other tough stuff, as the graphite acts as a self-lubricating surface and it lasts for several seasons before you'll need to tune it up a bit.

I built the boat below three years ago and finished it with Porch and Floor paint and graphite/epoxy hull bottoms. It's been all over the mountain west to lakes and rivers in the Grand Tetons, the Great Salt Lake and Lake Powell. All of these are places known for shorelines that deal harsh treatment to rec. boats. So, far, no appreciable signs of wear and it doesn't look like it will need a tune-up for, at least, another season.

Go price a can of Awlgrip and go down to the Home Depot and price a gallon of Behr paint as specified.

If you do go this route, let me know and I'll shoot you an email describing the full application process for best results.

[Roughrider24]

Thanks guys for the good responses. Mark... good info about the epoxy paint being a tougher material than gelcoat. I guess the challenge is then affording to get it to a suitable thickness (as gelcoat has thickness) to still survive multiple abrasive events. That K5 also sounds like some amazing stuff, but reading about the need for at least 1500 psi and 175deg F to adequately spray the stuff is a bit out of my league. Still quite interresting of how all the technologies are progressing!
Chris... Thats a gorgeous trimaran! I am really interested to learn more about the graphite powder mix for bottom paint, but I am not too sure yet about using Behr house paint on my Nacra. I am definitely in a listening and learning mode here and I appreciate your taking the time to reply.

Cheers from Gary in Texas

[jonr]

Does anyone know the hardness values of Awlgrip vs moisture cured polyurethanes (which I've been told are very hard)?

You could get even more wear resistance with a Delrin plastic runner along the bottom.

[themanshed]

I painted a Super Cat 20 with Awlgrip it came out great! The paint job is two years old and the boat has been raced hard 1200-mile still looks great. Make sure you follow the safety rules what ever you paint the stuff now a days will kill you. Here is link to the restoration. http://themanshed.net/archived-proje...percat-20.html (white boat)

I've also painted a boat with top quality auto paint base coat / clear coat urethane and added prism flakes to it. Not as durable but it was fun and looks really sharp on the beach (the tourist get a kick from it) in the sun when the prism flakes reflect all different colors. (Red & white boat) http://themanshed.net/archived-proje...catamaran.html

[Roughrider24]

Hi Mike... "themanshed".

Those Awlgrip'd Supercat hulls are beautiful!!! Did you use a fairing layer prep before applying the primer. What primer (and fairing material?) did you use? I have spent some time on the Awlgrip web site recently trying to learn about their process.

... and didn't you have trouble with flying insects landing on the hulls while painting without screens on the ends of the ManShed... especially painting at night with the shed lites shining bright?

Most importantly though, in the 1200 miles of sailing, did you drag your Supercat on the beach much, and how have the bottoms held up? Can you make any comparison for how the Awlgrip bottom ruggedness would compare with gel coat? Has the Awlgrip bottom worn through the top-coat layer and into the primer layer? I would assume that the primer is not quite as hard as the top-coat. Thank you for the great posting. Super infomation!

Cheers... Gary

[themanshed]

My friend keeps the boat on the beach and uses cat tracks but the boat gets beached also during the day. Alwgrip holds up better then gelcoat as Awlgrip is a much harder surface. He uses a little West to fill scratches. Then he uses enamel paint from a can to touch it up. Remember not much of the hull surface actually touches the sand. The primer is fairly hard but not as hard as the topcoat. Still harder then gel coat though.

All fairing and repair work is done with West System products 105 resin, 205 hardener, 410 fairing powder mixed with the hardener although I like 407 powder myself it is a bit more harder but takes more sanding. I stopped using poly resin and bondo a few years ago. The hulls as the picture on my website will show were in rough shape to begin with and needed major work / restore. I started sanding the boat with 80-grit and was down to 400 by time I was to prime. Remember paint is important but 95% of the job is prep work. I was lucky on paint day I did not catch any bugs, sags, or runs! Alwgrip flashes of pretty quick and it was a warm Florida day.

I had a NACRA 5,2 when they first came out fun little boat one of the first things I did was to take out the seam lines on the top side of the hulls and re-gel coat my work made it look really slick!

[Roughrider24]

Well... I think West System with Awlgrip on top is the direction that I will go as well. I have used West System in the past for below water-line repairs on a keel boat we owned (and for lots of other general fixes), and I always liked how easy it was to mix, how dependably reliable it cured, and the wider temperatures ranges that I could work with it. Like others, I became perplexed however to read on the forum postings that gelcoat isnt a real good option over epoxy... even though the West System web site says ... if properly cured, you can get good adhesion of gelcoat over West epoxy.

Like you Mike... I also intend to take out those hull seams that Nacra leaves along the top of the 5.2. Did you decide to run a layer of glass fabric over the hull seam first to strengthen the area and reduce chances of the gelcoat later showing stress cracks along the seam line? Did any hairline cracks in the gelcoat ever show up along those seams?


Thanks everyone for the good form post replys, and in a month or so, I will post photos of my effort, results.... and list those inevitable "oops" lessons learned.

Smiles,

Gary

[themanshed]

That was 30 years ago but I think I just sanded the seams down. If you glassed them over after sanding it could not hurt. Thought you may like the pic.

[aussiebushman]

I'd like to add my thanks to all on this topic. I recently acquired an A Class cat to use as donor items for a new trimaran - a Trinardo actually. The cat hulls are gelcoat/glass over thin ply with many areas requiring repair and it will not be feasible to work from the inside of the hulls.

I'm quite confused about potential compatibility if the repairs are done with West system or Botecote and what to use over the epoxy. From what others have said in this thread, am I right in thinking that after fairing with microlight thickened epoxy Awlgrip can be used for the finish coat?

If the remaining areas of gelcoat are well sanded, can the Awlgrip be used to completely recoat the entire surface?

Hope these questions do not infer hijacking this thread

Cheers

Alan

[Roughrider24]

Hi Alan,

Your good follow-up question caused me to go to the Awlgrip Website where I found an excellent Awlgrip published PDF file in thier product literature section called the North American Systems Giude:

http://www.awlgrip.com/support/liter...uide%208pp.pdf

The guide specifically says on page 3 of 8 that Awlgrip is intended to go over gelcoats, fiberglass, composits, wood... and lots of other applicaations listed on the following pages. They do also say that you need to use only their system of sealers, fairing compounds and finish primers to assure good performance of the topcoat, and to not mix any other components that are not manufactured by Awlgrip into "the AWLGRIP system". They even show an easy to follow chart on that page for what those recommended coating layers are. (Do you maybe think they are trying to discourage us from using our West System epoxy and filler for fairing?)

Your Trinardo sounds like a fun project.

Good reading, good luck, and good sailing!

Gary

[themanshed]

They always say that and for "wet products" you should try to stick to one product line that is compatible as a good practice unless you absolutely know that they will mix. It also takes away any liability from the manufacture should anything go wrong. Once the West Systems has cured, been sanded, and ready to paint you are good to go (with the proper primer and prep) Awlgrip over Wood, Metal, Epoxy, or Gel Coat.

Mike

[aussiebushman]

Thanks guys. The PDF info is very useful, but my take on some of the points might be a bit different to yours. The tech sheet actually seems to refer to not putting additives into the Awlgrip, not the use of Awlgrip with other systems and that makes good sense.

What worries me more is that their topcoats are specifically for above waterline application. However. since the amas are not strictly speaking below the waterline on any extended basis, I should hope the coating should be OK. The low point of each ama is actually level with the waterline of the main hull so immersion only occurs to a limited extent and I would not anti-foul them. I'll contact the local (Australian) agent but you guys might comment too, please.

Re compatibility with epoxy and gelcoat, the Awlgrip seems ideal. I certainly would never trust polyester resin for any repair to the damaged ply areas. My experience building a 30' cruising cat was with West System that generally was a great solution. However, I'm being persuaded that the Botecote system may be better mainly due to the claim that it does not exhibit amine bloom - a real hassle in low temperatures and here we are heading into winter and where I live in the mountains it goes to 10C below. Of course the bloom can be scrubbed off with water but it is a time wasting complication.

Gary is right that the Trinardo is a fun project. Kjell Neilsen is a great guy and very willing to share development information. He is using a Tornado for the amas and rig, whereas mine is an A class with slightly different hull shapes and a taller rig. I'll start a new thread and post pictures as the project progresses.

Regards to all,

Alan