Spraying Gel, some answers

[BenKeith]

Ok,

Spraying clear gel

Here's what I've found out about the stuff and Duratec

Minimum gun: 2.3mm gravity feed. Sharpe only recommends 2.3 gun with a pressure pot set at 5 - 8 pounds. But who wants to clean a pressure pot every 10 minutes. YOU WILL HAVE TO CLEAN GUN EVERY 8 MINUTES OR SO I'm told you can thin a little more than the 5% and use the gravity feed. You can find the sharpe Cobalt 2.3 HVLP gravity feeds for $109 at Tool Paradise.com. Harbor Freight has a $69 1.4 HVLP gravity feed gun on sale for $49 and you can order a 2.2 tip kit for $20. I'm using the Shapre, since I found one I can use for free.

Thin with 5% - 15% with MEK solvent. Supposedly styrene and others makes the finish hard and brittle.

Spray coats of gel coat with catalyst and let it sit for one hour between each coat.

For final coat mix Duratec high gloss additive and clear 50:50

After spraying it, wait 24 hours and sand orange peel out with 400 grit. Let it outgas another 24 hours and then start working up to your 1000 grit or what ever you sand to. It can be buffed out at this point but would be better to wait another 24 hours.

Using the wax additive in clear (if you don't use Duratec) is not recommended, It can cause the clear to cloud. Use PVA over the final coat of clear. Still go the the same process as above to sand out.

Make sure you have a very dry, very large air supply, the gun will use about 13 - 14 cfm. If any moisture gets in the clear it will make a milky spot. This can usually be worked out with a heat gun if you get it immediatly. You might want to look into a toilet paper filter and change it a couple of times.

Plan on doing lots of sanding. Seems all the pro's say you're gonna be sanding until your fingers bleed.

I have also found there are world of differences in the quality of clear gels. The cheaper don't last long before they start to yellow and haze over, So do your homework. I just hope mine's not one of those. I had already ordered it before learning all this good stuff.

Hope this helps

Keith Jones

[sho305]

Doing bodywork, the only way that worked to wet sand with power that I found; was to use an pneumatic 'jitterbug' sander running real slow. I would start this way to knock it down, and finish by hand.

[BenKeith]

Jitterbug is great and plan to use it where I can but there are so many concaves on mine, the edge of the pad might cut in, and that wouldn't make me happy. So it's still down to a ton of hand sanding.

Keith

[sho305]

The best paper I found is 'Nikken' wet paper. Cuts great and lasts. I use those foam wet pads you wrap the paper on if not blocking something out. Some soap in there helps. You ought to be able to start kind of coarse and cut your time on gelcoat. Just think of the forearms you will have after that! I have even used 320 on a DA before starting on rough stuff. Its about the same as 400 wet. I have buffed with the original gritty softscrub on old gelcoat, not tried on new though. You might know all this anyway.

I used this VC Performance Epoxy from Interlux on my Bayliner transom. I painted the well to about 3' up the bottom. It sanded real easy but buffed to a so-so shine. It was only a day later and it matches the boat perfect, so it is good. Think I will buff a spot later to see if it shines better. It sprayed like a dream. Used some brown tint to make off-white, but it only comes in white. I find it very irritating that there is not a better product for this that can be sprayed easily. I think this stuff is vinyl and epoxy based. Was only $38 for 2qt sprayable(the 2 parts in qt cans).