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Resin and Gelcoat Mixing

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Resin and Gelcoat Mixing
Hello all,

I have just received my tub of Resin, Gelcoat and my Catalyst. Just a quickie here... Do I put the gelcoat down first .. then lay on the fiberglass or is it truly a coat and goes over the fiberglass once you have applied the resin and have it laid where you want it?!

Thanks for any help!

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
i might be wrong but fiberglass needs something to block UV rays which is your gel coat

so glass 1st fill coats resin then gel coat
but if your working on a sneakbox or other duckboat thats going to be painted you
have no need for gel coat as the green/mud/tan paint your going to use will block
UV rays
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Re: Resin and Gelcoat Mixing In reply to
Thanks John,

Yes it's a Carsten's Pintail and is the Bottom of the boat. Just fixing holes in the Keels..


I was just interested in why they sent both.

Also - Is all silicon water insoluble? I am looking at finding some sort of filler for the seams that connect the top and the bottom.

Thanks for any help!

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
not sure about your 2nd ? if you are using epoxy resin and a filler (wood flour) to fill
seams or if very thin seams just epoxy
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Re: Resin and Gelcoat Mixing In reply to
Mikey,

The gelcoat goes on after the cloth and resin have cured. You will want to wet sand the cured mat and resin to smooth out the real rough areas and to get an anchor pattern for the gelcoat to stick to. Gelcoat is tricky too. Make sure you are wearing the proper protective equipment for all of theis work and know that the catalyst is an oxidizer and can cause severe skin burns. You want to be VERY careful when you mess with this stuff. Also, if you use to much hardener in the resin it can get extremely hot and I've heard it can ignite. Follow the mix directions.

I bought a medicine despensing syring for mixing my gel coat. I found a table on the web that showed how much for a 1.5% mixture. I used wodden craft sticks and heavy waxed paper cups to mix in. If you are doing the whole bottom of the boat with the gel coat, you will want help because you get about 15 minutes and the stuff will start to harden. My wife painted on the gel on one side and I did the other on my pintail and we had it covered in about 8-10 minutes. Also, once you put the gel on, don't keep going over it with a brush as that will just make it rough. I did two coats of gel on my boat with wet sanding after cure of the first coat. Then after the second coat cured for 24 hrs, I wet sanded the 120 on the high brush marks, then 180 grit, 220 grit and finally 400 grit. With the wet sanding you keep the glass from building up in the paper and als can really feel when it is sanded smooth. Keep an eye on it though because the 120 and 180 can take down some material quickly.
SHE THINKS MY DUCKBOATS ARE SEXY
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Re: Resin and Gelcoat Mixing In reply to
Hey Ron,

Yes Sir, I've looked at Walgreens and found some sort of Oral metered syringe so as long as I don't need a long nose on it I should be fine.. I did also receive the General Instructions from Carstens and the Ratio's.

I used to work as a water scientist / technician for a mine in MN and I still have my respirator and gear... I bought a mini Roller.. and just need
1.) Wax paper cups
2.) Stir Sticks
3.) New filters
4.) Syringe

I also realize that CC and mL are equal so I just want to start with some sheets of fiberglass.. and see where I can go from there.. I should basically glass the entire sides of the keel just to make it equal and start with small batches so that I can get used to it.

Sincerely and with Tussen Takk!

Mikey Lund


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
Gel coat is used to block UV rays from destroying your fiberglass. Gel coat is polyester resin with pigment in it. The pigment provides the protection. When a boat is laid up in a mold the mold is first waxed, then the gelcoat goes down, then the glass. Now understand that the gelcoat used in this process contains no wax. And of course the wax is what is used to create an air proof film on top of the resin to allow it to cure. Resin will not cure if it is exposed to air. Laminating resin contains no wax. That way the portion exposed to air never cures so one can come back the next day and lay fresh glass on it and still have a "primary" bond.

This "primary" bonding business is important. Polyester resin produces a perfectly good "primary" bond. In other words; when all the resin is layed up wet at the same time and cures at the same time then the bond produced is primary and strong. Polyester resin has very poor "secondary" bonding characteristics. In other words; if you stick fresh poly on something that is a solid surface aka...wood, fiberglass, (including glass using polyester resin,,,this makes no difference) then you will have a secondary bond, and a poor bond.

So, polyester resin and gelcoat are well suited for making hulls in boat molds. When this is done "ALL" the resin cures at the same time giving you a hull that is essentially one solid substance. Primary bond. The gelcoat will cure as soon as glass is layed on top of it, there-by cutting it off from the air.

You can paint gelcoat onto something and it will protect the glass underneath it. If you prep the surface well it will stick ok. However, gel-coat is a pain in the ass to work with. If you spray it then you only have a small amount of time before your gun becomes full of solid resin. You'll have to completely disassemble it and go through it very thoroughly. If you roll it there is no way to get a nice smooth even surface. I've tried. But it will be good enough for a work/duck boat. The fumes are horrible. Matching colors is very difficult. Quite an artistic en devour. Don't expect to ever mix up a batch of the same color twice.

Paint is a much better choice for top coating a fiberglass boat. It comes in a variety of colors. Is easy to work with. Depending on what you use it can provide wonderful protection. And it really is the way to go. If you're using gel-coat because you think your providing some super duper turbo awesome protection your a bit mistaken. The only really great thing to say about it is that you can pile it on real thick. But. To do this you will need to apply several coats. This will require you to sand the entire boat between coats to remove the wax from the surface of the cured layer. Not pleasant.

If you want some really amazing protection try barrier coat. 2000-E. Comes in grey and white. You follow the instructions and alternate between colors to ensure good coverage. This stuff is epoxy based. (which has amazing secondary bonding characteristics). If you paint your boat with this stuff it will be impervious to everything. Bullet proof. Then top coat with some paint.
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Re: Resin and Gelcoat Mixing In reply to
There is wax added to the gel coat that I received from Carstens. This stuff does cure. Paint will cover for UV protection however the gel coat prevents hydrolysis from happening by giving a thick enough barrier coat between the water and the glass fibers. The gel coat from Carsten's had pigment added to it to closely match the factory colors of their boats and provide the UV protection. In this repair case...the gel coat is the last to be applied.
SHE THINKS MY DUCKBOATS ARE SEXY
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Re: Resin and Gelcoat Mixing In reply to
Yes...don't roll this gel coat. Get some natural bristle tapered brushes and brush it on.
SHE THINKS MY DUCKBOATS ARE SEXY
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Re: Resin and Gelcoat Mixing In reply to
Ron, John and John,

I finally have everything I need to start fiber glassing. I was waiting on the proper filters for my respirator. So I have planned that I will cut the glass, then after mixing my catalyst and resin apply and soak all the fiberglass. Once it's saturated I will use the mini-paint roller and smooth out. I was wondering if I should try to build some sort of Berm so that the resin won't drip down the side of the boat? do people do this? and if they do should I be careful to use a hard plastic so the resin won't melt it to the boat?

I am going to start with a small batch as I see no problem with only applying to a portion of the glass at a time to make sure I have proper mixing ratio and of course being efficient with my time.

Thanks again for all the help. I talked to a pharmacist at Walgreen's and they gave me a free medical 5mL syringe. Nice people here..

Thanks again so much guys, I hope to be of help to others here as well to give back with all the help and kindness I've received here. Will be donating to the site very soon!

Sincerely,

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
Well the First layer and coat is on the Boat. I tried a small area with the graduated syringe and a small piece of glass. Once I shaped it I just thought well lets do this. So I'll show you how it went and if anyone see's any problems please let me know. Otherwise I will let it cure over night and either add on or if its enough to do the job - start sanding tomorrow.

Thanks again!

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
Looks good but you should have filled the holes with something prior to glassing over them. As you can see you know have air pockets where the holes once were. that is a weak spot. By filling with bondo or some type of filler you would have avoided the air pockets. what oz. is the matt they sent you to use? and how many layers you putting down? as if you use 3-4 layers of atleast 1 1/2oz it probably will be plenty strong even with the air bubbles.
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Re: Resin and Gelcoat Mixing In reply to
Tony,

I went to Ace looked at Bondo and other filler putty. I really didn't know how to do it and didn't want to spend the money on something that's definitely a first for me. This is my first time doing anything like this and everybody on here has already been really helpful and I'm sick of being a bother for people. So this is what it is.. I planned on putting down one layer of glass, then another narrower layer of glass over the voided area.

I did want to put some sort of back bone in there but like I said.. first timer. I'll throw another glass layer over the top and be careful with it this year. I will only be in Nevada this season and then off to Alaska for Colorado. So I wanted to get it out there on the water soon.

Thanks for the input! Appreciate it!

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."
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Re: Resin and Gelcoat Mixing In reply to
Mikey, Get some Cabosil, Microballons, fumed cilica, low dinisity filler, sawdust, anything.....Mix it with your resin until it is nice and thick. Use this stuff as your filler/bondo agent. Don't use bondo. It's not for marine applications. You can grind out the areas of your repair where the voids are and then fill them with this resin/filler mixture. Then glass the small areas over again. You really don't want to leave voids in your lay-up. If you go ahead and fix this now it will save you some headaches in the future.

Otherwise, things look fine. Glassing is not brain surgery. Especially if you don't care what the finished product looks like. Just make sure you fill all voids 1st, then cover with glass, then sand and topcoat with whatever your using. Remember. The more you sand the less strength and material you have to keep the water out and the dings away. Use more glass than you need so that when you sand it there will still be enough left to do the job. And...... you can't go wrong with making your top layer of glass out of chop-mat...It sands easy, is cheap, and leaves a lovely even surface to top-coat.

No one here minds giving a little advice. Please feel free to ask as many questions as you want. I want your project to turn out great.
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Re: Resin and Gelcoat Mixing In reply to
Mikey, I just took another look at your pictures. Did you lay fresh glass over gel-coat? It looks as though you did. If you did this then you have a problem. You must remove any gel-coat from a surface you are going to glass. You glass to glass. You do not glass to gel-coat. The best way to remove gel-coat is to grind it off with an angle grinder. There is an attachment you can buy for about $20 that is called "Grit Lock"... You use this to attach discs made of 25 or 36 grit sand paper. Using this you can remove alot of gel-coat in a reasonable amount of time. You can also just use a regular grinding wheel but it will leave a really nasty surface that will need sanding.

Hopefully the pictures are misleading but if there not you really need to redo your repair.
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Re: Resin and Gelcoat Mixing In reply to
Looking at the large photoa that shows the long strip over the keel looks alot like my boat did when I got it repaired by Carstens. The gel coat was sanded before applying this cloth and resin so this repair should stick. I think I would put the second layer on just as wide and long, then once cured wet sand it and blend the edges to the hull. It's a repair not a new build...sure looks like the keels kept shape..Just my two cents.
SHE THINKS MY DUCKBOATS ARE SEXY
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Re: Resin and Gelcoat Mixing In reply to
John and Ron,


Hey again and thanks for the feedback.. I did NOT use any gelcoat yet. I simply mixed the resin with the catalyst and soaked the glass and molded it with my gloves. I used a mini paint roller to smooth out any areas that had a heavy resin deposit.. I was worried about leaving those holes void like that. I realize the weakness i've created and now that I've laid glass I think I would be comfortable cutting it out and doing as you say.. Resin mixed with catalyst mixed with some sort of sawdust, chip, fine mix.

I just wanted to get it done and when I started (not have done this before) I just started going to town because I figured the majority of my tools that I purchased for this use are going to have a short window of workable function for me.

I think you are right also Ron, in the sense that after I cut it out and fill the voids in my keels, I should go over the keels again with full sheets to really give it that rough and tough durability. I have half a qt. of resin left and haven't opened the gel coat yet, plus around almost a dozen sheets of fiberglass to boot.

Thanks again for the help guys i really do appreciate it! Not trying to be a burden here, I just love these boats and hope to someday gain the experience to build my own and then get my kids into these crafts as well.

All the best!

Mikey


"There's no place I'd rather be than with my best pal Odin, awaiting the Wings."