I recently acquired a set of Goldberg builtup floats that are almost ready to finish. After sealing a few holes with epoxy and filler, I plan on painting with Enamel paint, and spraying a coat or two of Minwax Polyurathane clear over that. Am I way off base or does that sound like a plan?

Sounds ok to me. If your cub is fabric covered, I would suggest using a satin poly as opposed to a gloss.

Actually they will be going on a Monokote covered Sig Hog Bipe.

Are they glassed?? The bottoms take a lot of abuse beaching, and sitting on sand (or gravel).....

I have some fiberglass cloth, I never considered how much abuse they will take on the bottoms. I assumed that the plywood would be strong enough with the enamel paint and polyurethane clearcoat. The seam on the bottom is already glassed, is that sufficient?

I fiberglass floats for two reasons:

1) makes them really waterproof

2) Double up the fiberglass on the bottom to account for abuse, rocks, sand, gravel and such. My last pair of floats had the first fiberglass cloth and then put a 2" wide of fiberglass strip down the middle bottom of the float.

Good luck!

Thanks! I will break out the cloth and glass the bottoms completely. Any other tips for finishing after I glass?

I went to the local "mart" and got some fiberglass cloth. It's pretty heavy stuff from made by Bondo, but it works great. Super strong and not too heavy when finished. I only glassed the bottom part from the step forward. I know alot of you will say glass the back half also, but I figure the polyurethane coats will make it tough enough to survive. I am using Rustoleum enamel paint before I lay on the poly. I'll try to post up some pics this weekend.

Don't use fibreglass cloth that you buy at Walmart.That is a 6oz. cloth and is way too heavy for float use.Use a 1 1/2 to 2 oz. cloth to glass the entire float top and bottom.Some will use a 3/4oz. cloth on the upper portion but I personally don't like using cloth this light for float use as it is just too easily damaged from shore and floating water debris.For ease of use and smell tolerance,I use Z-Poxy finishing resin and it is very easy to work with because of its long pot life.Gives you plenty of time to position everything and get any bubbles or wrinkles out from under the cloth etc.By glassing the entire float you are not only strengthening the structure as a whole but also sealing the wood from any chance of water penetration.You will find that your paint will also adhere better and your floats will also last a lot longer.It's a lot of extra work but the finished product can not be compared to a plastic film job or just painted wood.It's way better than that if you take the pains to do it right.Mine are almost 10 years old and they just keep on trucking,and I DON'T baby them when I'm flying with em either.They show absolutely no signs of water penetration or paint adhesion problems.Be careful though,just because its glassed doesn't mean its bullet proof.It can still be easily dinged and dented if your not careful with them.It just takes a liitle more carelessness to get them that way

Hi!
2 layers of 25g (1oz) cloth well do fine.
Regards!
Jan K
Sweden

Some enamels are not fuel-proof. It would be a shame to see your nice shiny covering job turned into a gooey mess.
Check your paint for fuel-resistance by painting a piece of scrap in the shop,then exposing it to a splash of fuel after it dries. check it the next day.

That's absolutely correct Jim.There are a lot of different types of paints out on the market that are NOT fuel proof unless they are top coated with some type of polyurethane type finish such as Varathane.Unfortunately,a lot of manufacturers of paints for the hobby business seem to be dropping a lot of the old standard paints that we use to once use with great success such as for example,K&B Epoxy paints and Black Barons line of paints which I use to use quite a lot.I would buy a pint of paint,thin it and spray it myself.The end finish was twenty times better than any off the shelf spray bomb.The problem with a lot of spray bomb type paints is that they have a very high percentage of thinner and a very low percentage of colour pigment in each can which means it takes more coats to cover.More coats means more chance of paint runs and negative reactions to the existing layers of paint that are already applied.If you read the can ,it will give you recommendations telling you to spray subsequent coats within so many minutes of each other or else you will have to wait like another 3 months before top coating again.If you don't follow this advice to the letter,you'll end up with one hell of wrinkley,gooey mess.The solvents in some of these paints react just like paint stripper if you use them improperly.Read the directions carefully and apply to the letter.To be safe,experiment a bit first in advance just so you are familiar with the paints,drying times and how they will react with one another.Better to screw up a sample piece than your actual floats right?After all is said and done,it really isn't as difficult as it sounds if you tackle the job knowing some basic facts first.Chalk up the experience as part of your gradual learning curve.You'll be pleasantly surprised to find out later how much of this knowledge about glassing and painting will come in handy down the road when you take on future building projects.Good luck finishing your floats.