Hull finishing help please.

[dpcdvm]

I am currently building the USS Crockett RC model by Dumas. I had a very smooth, nice looking hull after fiberglass and paint. I had the bright idea to put on a coat of slightly thinned 2 part epoxy. It looks like crap now. I'm guessing I need to sand smooth, but then what? Any advice is greatly appreciated. Thank you.

 

[AndyA]

How, exactly, does it look like crap? Is the epoxy bubbling or peeling in places or is it adhering but lumpy? Can't really tell from the photos. If it is bubbling or peeling I'm afraid that you have to sand it all off. If it is just lumpy, you can probably sand until smooth and repaint. BTW avoid applying epoxy over paint whether you're gluing or finishing. Fair winds!

 

[dpcdvm]

Thank you for the reply. It is not bubbling or peeling, just lumpy and not smooth. Sorry, the pics don't really show the surface. This is my first model RC and this big. I have no experience with epoxy and did not know not to apply over the paint. I was looking for some protection to the hull. Thanks again!

 

[Graham]

I would go at it with some 120 grit on my palm sander - gently.
Move to wet & dry paper.
Undercoat and sand smooth. Repeat if necessary.
Finish with an enamel paint - a rattle can would work well.
Cheers.

 

[Bob Cleek]

I would go at it with some 120 grit on my palm sander - gently.
Move to wet & dry paper.
Undercoat and sand smooth. Repeat if necessary.
Finish with an enamel paint - a rattle can would work well.
Cheers.

Yes, do as the man advises. Use a compatible sanding undercoat, then prime and finish coat on top of that. Be sure your sanding undercoat is compatible with the epoxy. If not, use a compatible primer on the epoxy and then your sanding undercoat. Preparation is 90% of the work in a good paint job. Use a quality oil-based alkyd enamel on the hull for the finish coat. If your hull is smooth and free of cracks, you should not require anything more than your enamel finish coats to protect the hull from any water damage. RC boats aren't in the water for long periods of time and are stored indoors. For some reason, somebody seems to be giving the new RC hull builders the impression that they have to slather their hulls with fiberglass resin or epoxy to "protect them." There's nothing wrong with either, except that it takes a bit of experience to apply any resin and fabric lay-up and most make a dog's breakfast of their first couple of attempts until they find somebody to show them the ropes.

 

[dpcdvm]

I would go at it with some 120 grit on my palm sander - gently.
Move to wet & dry paper.
Undercoat and sand smooth. Repeat if necessary.
Finish with an enamel paint - a rattle can would work well.
Cheers.

Thank you!

 

[dpcdvm]

Yes, do as the man advises. Use a compatible sanding undercoat, then prime and finish coat on top of that. Be sure your sanding undercoat is compatible with the epoxy. If not, use a compatible primer on the epoxy and then your sanding undercoat. Preparation is 90% of the work in a good paint job. Use a quality oil-based alkyd enamel on the hull for the finish coat. If your hull is smooth and free of cracks, you should not require anything more than your enamel finish coats to protect the hull from any water damage. RC boats aren't in the water for long periods of time and are stored indoors. For some reason, somebody seems to be giving the new RC hull builders the impression that they have to slather their hulls with fiberglass resin or epoxy to "protect them." There's nothing wrong with either, except that it takes a bit of experience to apply any resin and fabric lay-up and most make a dog's breakfast of their first couple of attempts until they find somebody to show them the ropes.

Thank you for the response. The fiberglass, sanding, priming and painting went well. Hull was not perfect, but very smooth and the only problem areas were around where the running gear was installed. I did have the impression I needed more protection and the epoxy was a big mistake. I have been building more traditional sailing ship models for years and this was my first attempt at a large RC ship. Live and learn, I appreciate the help and wish you the best. Neil

 

[Rafico]

I am currently building the USS Crockett RC model by Dumas. I had a very smooth, nice looking hull after fiberglass and paint. I had the bright idea to put on a coat of slightly thinned 2 part epoxy. It looks like crap now. I'm guessing I need to sand smooth, but then what? Any advice is greatly appreciated. Thank you.View attachment 487637View attachment 487636View attachment 487635

Sand it again very well and then you can paint it with regular paint like Krylon fusion or Rustoleum, both are water resistant. I painted my in that way about 2 years ago and so far I didn't have any problem , those paint are drying in 10 or 15 minutes .

 

[raybois1]

Thank you for the reply. It is not bubbling or peeling, just lumpy and not smooth. Sorry, the pics don't really show the surface. This is my first model RC and this big. I have no experience with epoxy and did not know not to apply over the paint. I was looking for some protection to the hull. Thanks again!

To show defect on a smooth surface, use angled lighting. You'll then have shadows which will highlight the bumps, hollows, and scratches, etc.

 

[dpcdvm]

Sand it again very well and then you can paint it with regular paint like Krylon fusion or Rustoleum, both are water resistant. I painted my in that way about 2 years ago and so far I didn't have any problem , those paint are drying in 10 or 15 minutes .

Thank you for the response and best wishes, Neil