How to remove Fiberglass boat oxidation

 

A. Lou,
you say you have heavy oxidation but you sure don't say if it's above or below the water surface, do you?

My first suggestion would be to contact the boat manufacturer. If that doesn't work out, contact any FRP boat mfg.

Fibreglass doesn't like abrasion. If properly made, the outside would have a gel coat. This would be a thin coloured coating and would protect any fibres and SHOULD GIVE u.v. protection... if the right 'mix' were used.

Personally I've never heard the word 'oxidation' applied to fibreglass unless due to severe, mainly oxidizing acid attack. And your using a buffing compound to 'grind down' this problem will only make things worse.

Boat resins use just standard aliphatic polyesters, you don't need better (sic. acid resistant) ones. Try also the local supplier of fibreglass type resins. They could/should be able to help you ... and for advice on how to properly apply any coatings, a local frp fabricator will gladly give you some good advice, if you beg properly!

A. I also have a sailboat of approximately the same vintage as yours. It too, is dark green. The "oxidation" you are referring to is known as "chalking". If you live in a sunny area (such as Florida), a dark hull will chalk faster than in Northern waters where the boats may be under cover during the winter months. Dark hulls are beautiful when new, but are hard to keep looking good. The hull on our boat has the worst chalking on the starboard side. It is the southern side as the boat sits in the slip at the marina. I have tried my best to wax the heck out of the hull. Most marine waxes have UV inhibitors and that helps. However, since we bought the boat used...and the previous owner never worried about wax, we cannot bring back the deep color shine (no frosty whitish areas) that has already been lost. We were told by the manufacturer of the boat and several boat yards, that our only real solution was to paint the boat. Sigh. Paint has its own drawbacks, but I have seen beautiful, deep-blue Hinkley sailboats on the water. They have been painted with Awlgrip ⇦this on eBay or Amazon [affil links] type paint. Hinkley is a very reputable boat builder (and way too expensive for us to own!)who will not sell a dark gelcoat hull for exactly this reason. Someday, we will probably have our boat painted. Don't sand through your gelcoat trying to find that beautiful deep-colored shine....

There are "gel-coat restorer" products on the market. Read "Practical Sailor" magazine [at www.practical-sailor.com] before trying any of these. Practical Sailor is the Consumer Reports of the sailing world. If you are a boat owner... I would recommend you subscribe. It has saved me a lot of time (and money) trying products that really wouldn't do what I wanted. (PS...I have NO affiliation with the publication. This is just my personal opinion).

Good luck... and Safe Passages,

 

According to the messages, the chalking can be easily removed by chemical way. Phosphoric acid will be a solution. Please try. There is a product in US and in China made of Phosphoric acid for rust cleaning can remove the oxidation. Please try.

There is a small skill if you can not get this product easily, just buy 250 cc 75 or 85% phosphoric acid, mixed with 1.5 liter of water. Use it to brush on the chalking area. Hold for few minutes, clean with water. Most of the chalking will be removed. Use rag clean the rest. Please let me know the result.

It doesn't look like anyone has responded to you in the five years since you asked this question, so by now, you probably don't have the boat anymore.

If you do have the boat still, you're problem is 5 years worse.

If you're there still.... do you still have the boat and am I right that it's worse by now?
If your answer is yes, can you upload a picture?