epoxy or poly for bow/keel reglassing ?

[DeepBlue2010]

If I am painting my boat I would only go for a high quality marine paint like AwlGrip or Interlux Perfection. These are very durable product formulated to be brush-able.

But these are also relatively expensive product and I wouldn?t spend that much money just to paint the keel area. IMO, your best option is to gel it, this option is very appealing now specially that your are considering a keel guard. This means no sanding, fairing or polishing after applying the gel is necessary. I would get me few short nap rollers from a good marine supply store or if you can find a good and knowledgeable sales person in Home Depot or Lowe?s, he/she can show you what short nap roller you can use on the shelf. You don?t have to throw them off by saying that you want to be able to handle gelcoat, most likely they will not be familiar with that name; just grab a 3M poly resin container (not to buy, just to show the sales guy) from the shelf and tell them to show you a roller that can handle it.. Gelcoat is pigmented poly resin

Anyway, with this roller, spread some gel on the area until it covers; repeat if you want after the first goat gels.

 

[bassmanhb]

thanks guys, i don't plan on beaching the boat at all but thinking about the keel gaurd just as an extra precaution to help protect the repair.....

 

[JASinIL2006]

If the repair is done well, you shouldn't need a keel guard to protect it. Personally, I wouldn't bother with it unless the keel regularly gets beat up when loading on the trailer (in which you have a different sort of problem) or you plan to beach.

 

[bassmanhb]

deepblue or anyone

in your post you said gelcoat is just pigmented poly resin right ? so in stead of using the gelcoat would it not be easier (and cheaper) to add a pigment to the final coat of polyresin when fiberglassing ? just wondering...... haven't had a much chance to work on the boat since been rainy and cool hopping to get back at it over the weekend and monday is supposed to be warmer and no rain.... also hoping my stuff i ordered comes by then ..


bass

 

[DeepBlue2010]

To my knowledge, Gelcoat is formulated from polyester resin. Pigments and thickener such as cabosil are added to modify the resin and add color, and UV protection. Are these the only modifiers added to the resin? Is it the same exact resin that is used for lamination or is it totally different resin with different chemical composition? I am not qualified to answer these questions. Maybe ondarvr will chime in.

When I mention that gelcoat is pigmented polyester resin, my intention was to address the compatibility issue so you don't wonder why I am asking you to grab a can of polyester resin and ask for a roller for it while you are trying to roll gelcoat. So basically I was saying they are the same thing as far as the equipment to deal with them are concerned. To a great extent the statement is true but I did not think you will take it to the extreme and try to make your own gel

 

[bassmanhb]

lol deep..... not to the extreme was just curious and not wanting to make my own ...... i do have gel coat on the way, just taking awhile to get here with ground shipping due to the mek ... been doing a few other things in the boat while waiting for stuff..... and still trying to figure out how to lift the bow higher to get easier access while working on it ...

 

[DeepBlue2010]

Use the tongue jack with blocks under it. Do you have engine hoist?

 

[gm280]

deepblue or anyone

in your post you said gelcoat is just pigmented poly resin right ? so in stead of using the gelcoat would it not be easier (and cheaper) to add a pigment to the final coat of polyresin when fiberglassing ? just wondering...... haven't had a much chance to work on the boat since been rainy and cool hopping to get back at it over the weekend and monday is supposed to be warmer and no rain.... also hoping my stuff i ordered comes by then ..


bass

bassmanb, I actually did what you are talking about. I bought 435 laminating polyester resin and some liquid gray pigment and mixed them up. And I applied that mixture with CSM (Chopped Stand Matt) to the insides of my rod boxes and storage areas to waterproof them and color at the same time. And it did come out nice. But I have not tried it as an outside the hull final coat to replace Gel Coat. While I understand that both Gel Coat and Colored Polyester Resin are very similar, there is enough difference to not substitute Colored Polyester Resin for Gel Coat. I searched all over the net for what is the difference and honestly all I ever read were they are different. But not one article explain how or why. However, I would go with the real thing, being Gel Coat if that is the way you were thinking. JMHO

 

[bassmanhb]

i should clarify a bit i need to get the bow up off of the trailer, as the front cross over of the trailer is in the way to work on the front keel area......

 

[bassmanhb]

gm, thanks yes i agree not much info out there about the difference between the 2..... and i do have some total boat gelcoat and hardner on the way along with some mustard pigment to try and match best i can the original color....

 

[DeepBlue2010]

i should clarify a bit i need to get the bow up off of the trailer, as the front cross over of the trailer is in the way to work on the front keel area......

Oh.... I see

Can you post a pic of the trailer setup. Maybe the cross member could be removed temporarily. I think a picture would help

 

[bassmanhb]

deep in the lower part of the picture you can see the cross member... i wish it could be removed but it is a welded trailer so no love ..... i will figure something out maybe i will have to just jack it up and use some cinder blocks with wood and carpet covering them...

 

[DeepBlue2010]

You might find this read interesting
http://www.customboatrepairs.com/jm...oat-from-a-trailer&catid=3:diy-tips&Itemid=17

There is a slide show at the very bottom. make sure you flip through the pictures.

 

[bassmanhb]

deep, thanks for the link... i was planning on using 2 2x4's and 2 cross braces with carpet on them like bunks on the trailer..... held up with 4 jackstands.... this should give plenty of support..

 

[bassmanhb]

well the last of my supplies that i need to work on the boat should be here today, so maybe will get something done and post a few pics if the rain holds off saying rain again for the next few days

 

[bassmanhb]

well of course its raining today and forcast doesnt look for next couple days so no work will be done on the boat...... but i do have a question ? how much chopped fiberglass should i add to my resin and cabosil (for PB) if im using 8 oz of resin mix ? do you just eyeball it till it looks good ? thanks

 

[DeepBlue2010]

What are you planning to do with the PB?

 

[bassmanhb]

deep, im going to be using it to fill in the larger areas on the keel to get the shape back.... (2 flat spots now) then fiberglass over that to finish it off .... if the rain ever quits so i can work on it anyway

 

[DeepBlue2010]

To answer your question directly, cabosil is just a viscosity modifier. It makes the resin thick. That is it. How thick? is up to you and what you want to use it for. In general, we mix it to the consistency of peanut butter (hence the name). Some people also add a handful of 1/4 inch cut of CSM and call this a "structural" PB.

With that said, I would not advice you to use this mix in this application at all. If you study the recommended ratios of fiberglass to resin in a layup, you will find that adding a handful of 1/4 inch cut of CSM doesn't even come close to the ratio recommended. If you are using poly resin,the result would be a very brittle mix.

I would trace the shape of the low spots on a transparent film with a sharpie then use the template to cut the pieces out of 1708, wet them and install them the smallest ones first. Now, this is a glass filling. You can then use the PB mix - or any other marine grade below water line filler - to fill and fair.

 

[Woodonglass]

When you say the larger areas, How Large and How deep? There is ONE other type of PB and that's something we call "Tiger Hair" Mixed the same just use 1 1/2" strands of torn up CSM. This makes and extremely durable filler. It IS very hard to sand and shape so you want to make sure and spread it as smooth as possible to minimize the amount of sanding. You can always make some "Fairing Filler" to make it PURDY!!!!

Mix ratio for 8oz of resin would be 12oz of cabosil and then add about 1/4 cup of fibers or strands. This is a good start and you can add more to suit your taste.

If they aren't to deep then I'd agree with DB and just use resin and glass. I would say to use CSM as your last layer, much easier to sand and fair.