Paint Vs. Gel-coat

[Trayder]

Hello guys- I wrote this on another board a while back:

I have re-gelcoated 3 boats and will be doing a 4th this spring, my 20 ftr. I will share with you what has worked for me.
Depending one where you purchase your Gel-Coat, it is NOT more expensive than Awl-Grip or Imron. The last boat I did, A Mako 19, a Gel Coat jobwas 1/8 the price of an Awl-Grip job (doing it myself)

Granted we used plain white gel-coat.

The prep work was easy.

1. Sand to original gel-coat (if previously painted), fill cracks dings etc with a polyester based filler or resin.(some say you can use Epoxy, just get rid of the ameine(SP??) blush.

2. Sand entire hull with 80 grit sand paper. Make sure you keep the sander flat against hull.

3. Wash hull with Acetone Tape boat. Trailer etc

4. Figure your working time with the gel-coat. Mix enough Acetone into the gel-coat so it will pass through your sprayer. I add the following way in a 2 quart mixing pail:

1: Add Gel-Coat
2: Add reqd' amt of MEKP
3: Thin with Acetone
4: Mix Thoroughly

Mix a small batch and time how long it takes to kick. REMEMBER this time. Temps Humidity, etc change things.

5. Mix a batch and begin spraying/rolling. Stop 1 min before the kick time and run to a waiting batch of ACETONE. Empty sprayer and douse everything with acetone, run acetone through sprayer assuring nothing will cure in sprayer.(VERY IMPORTANT)

6. While cleaning have someone mix another batch and begin spraying / rolling again.

7. Do this process until the boat is cover to 22mils of Gel. Took 3 coats on a Mako 19 using 1 gallon of gel coat.

Now the hard part:

The boat will now look terrible depending on your spraying skills, all orange peel, some runs etc. I am not a skilled sprayer so your skills may be better. Do not fret if it looks bad. The beautifying stage with gel-coat comes last. (for me at least)

1. For white/light color boats: rum Dye-Kem over the entire hull. Dye-Kem is a blue dye used when cutting sheet metals.

2. Begin sanding, making sure you keep the sander flat against the hull. Begin with a grit you feel comfortable with, do not cut too much. Some start with 120 other 100 and some 80 grit.

3. Stop and move to next section when the blue dye disappears. The blue dye shows the peaks and valleys so when it is all white you know to stop.

4. Switch grits up to desired finish, some 1000 others 1500 2000 etc.

5. Compound entire hull and wax.

Thinking about it,Gel coat is more expensive for a professional job as it is labor intensive. Material wise I have found it to be much less expensive.

1. Gal of Gel-coat w/ MEKP plus wax additive $50.00 From LBI Fiberglass

2. Acetone LOTS OF IT!!! $30-50

I am sure there are other ways of doing this process. This is the way that works for me. I have yet to roll gel-coat but plan on doing rolling the next boat.

Good Luck

[Trayder]

As for durability, I do not think Gel-coat is much softer than any two part paint.

However, you will not have to wax a two part paint finish for it to shine, the shine will last for 10 years

You will have to wax gel-coat at least annually for it to last.

[EBEACH]

The $4 sprayer that I mentioned will spray 16oz.(according to mfg.) It’s great for experimenting and repair work. For spraying the whole boat, I’d get a real get coat spray gun like this http://www.fiberglasssupply.com/Prod...gel_coats.html You can use a regular spray gun, but I’d make sure you have all the flow rates and pressure settings correct before trying apply gel. If you’re not laying it on fast enough, it will harden before emptying the can. Like Trayder said, The clean up is more work.

I’m not questioning which finish is better (paint would probably win), but which is easier to apply for the average DIY owner. If you apply 4 coats of paint, aren’t you sanding 4 times and spraying 4 times?

As far a color goes, I’d mix one large batch to do the whole job. Use white gel coat and color to get pastels, or neutral gel coat and color to get brighter colors.

Has anyone used an “air file” or “straight line” sander? It’s used by auto body repair shops. I would think this is a must have item for doing large sanding and fairing jobs.

[RingLeader]

I see this topic hasn't been touched in over a month, but I'm gonna reply anyway. Trayder is a phenom, I've drooled over his work several times. But, here are 2 products which will make spraying/finishing gelcoat much easier.

1) Duratec High Gloss additive (Available from Fiberglass Coatings Inc. www.fgci.com It is added to the gelcoat 50/50 and will make the gelcoat flatten out very nicely upon spraying. This leaves you with alot less sanding.

2) Minicraft Spray Reducer is what I have been using.Minicraft Reducers It is added at 30% by vol. to the gelcoat and does the same thing as the Duratec. It comes in different cure speeds which will adjust the working time. I use the fast for small jobs, but for a big job I'd use the slow for greater working/pot life.

I use Minicraft gelcoat which is custom computer matched to my boat's gelcoat. I sent them a piece of gelcoat from my boat, and they matched it with their computer. Now every time I order a quart of gelcoat from them, they pull up my formula and mix it up. The other important thing is to have them add wax to the gelcoat. This will do away with having to overspray with PVA.

Here is a pic of a boat built from scratch without a mold, and the builder used gelcoat with Duratec High Gloss additive. Hammer 30' CC

[Finster]

Very nice.......nice star filter too.

[Mark]

yeah Finster, you just wait till my project boat is done if you think that twinkie filter is nice: I'm going with one of those tacky Cokin "speed" filters while it is photographed sitting on a trailer [img]images/icons/grin.gif[/img]

[John R]

Photo Nerds!

[Finster]

I'll be right there with ya bro!