In this issue of the Composite 101, 202 and Advance Newsletter:

1. AN FRP QUESTION FROM SUBSCRIBERS.

Subscriber’s question by Jim Pintar :
-“The fiberglass on my boat is fading. Would wet sanding bring back the shine? If so how do I wet sand fiberglass?”

Composite 101, 202 and Advance answer:

Fading gel coat is common especially in older gel coats. Gel coats that date before the 90’s are made with lesser quality UV protection. This can be seen on the red colored gel coats the red turns like a pink; this is the sun pigments fading and even if you sand the gel coat, it’s faded through.

But the fading really come from different of sources. As we just discussed its maybe the sun’s effect or simply the normal wear, like the rubbing of a rope on the deck of a boat for example or maybe dirt that is stick on the surface and sometime chemicals can cause the lost of shine on the gel coats.

Sanding is the last resort solution. The gel coat are fairly thick comparing to a car paint which is near 5 mils. The gel coat in large productions often has between 12 and 15 mils, bear in mind that 12 mils is something like only 3 paper sheet thick. So if you are sanding you can easily sand through the gel coat that is why we say it is the last resort solution.

There’s a quick fix you can use to hide scratches or dull spots on a gel coated part. The effect of this quick fix will last only a limited period of time but the result ig quite good. Use pledge ( the furniture care product) of a similar product. Try it you’ll be surprised by the results!

The real solution to bring back the shine to a part is to use a buffer with a proper polishing compound.

First the buffer. It has to be a variable speed polisher 600 rpm to 3000 rpm. This is important that it is variable so you can vary the speed so you won’t burn the gel coat. The heat build up under the buffing pad can be quite high you got to be aware and use the polisher with a constant motion. **** DO NOT USE A BUFFER they only have a single speed and it’s too fast! If you burn the gel coat you won’t be able to sand off the burn it goes all the way through the fiberglass.
Then the compound, I like Aqua-buff 2000 from Duratec it’s easy to use; apply and remove with the polisher. You can use it with elbow grease but the result won’t be as impressive. Plus it’s a water based product so it’s easy to clean the polisher and buffing pad!

This is the only really solution bring back a shine to a dull part. Happy polishing!

Available at Guide.FiberglassTechnique.Com

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