What is Gelcoat?

[Greg Nichols]

Hope this is not a highjacking......



My dad wants me to do his boat, I`ve not seen it in a year, but remember it has oxidation. Like a Car do you Clay the gel first then compound, or no Claying needed?

[SShine]

Hope this is not a highjacking......



My dad wants me to do his boat, I`ve not seen it in a year, but remember it has oxidation. Like a Car do you Clay the gel first then compound, or no Claying needed?

no need to clay. just wash or pressure wash (pressure washign make things so much easier), then you compound it. I actually left my marine stuff at home and had to do a boat for my dads friend while on vacation so I used my OHC and an orange LC pad and it works great. Foam pads gunk up pretty fast on gelcoat though, I used 3 pads just to do the hull. if its white you wont have to polish or anything after you compound, on a darker color boat you might have to, depends. just make sure you get ALL of the oxidation off, you might have to compound each section 2 or 3 times to get rid of it all. its very time consuming. if you dont get all of it off, the wax will stain where the oxidation is and look like crap.



Have fun....

[bcddd214]

Gelcoat completely blows topcoat paint out of the water in every aspect.



Fact: Gelcoat has less UV protection but if you are not waxing your car or boat every month (yes, every 30 days), then you are WAY outside of your maintenance schedule and you jacked the finish up anyways.



Paint is thin and very pliable. Great for an unstable surface like the thin aluminum on cars but the first time that metal flexes, the Gelcoat will pop off because it is HARD with enough flex for a sold and stable surface. (A finished surface should be mildly more flexible than the surface it is covering to be a solid bond)



Gelcoat is highly manageable and easy to work with if you understand it. (There is a reason many gelcoats from the can do not get completely hard and tack free right out of the can after kicking it off with mekp!)

They have a really good website with tons of great info on gelcoat here Boatcrafts.org • View topic - The gelcoat howto is here.

[Thrillseeker]

I used to build fiberglass fishing boats and I can tell you Gelcoat is pretty tough stuff once hardened. Gelcoat determines the color of the boat. After the mold has been cleaned, polished, waxed and sprayed with mold release it is sprayed into the mold. Several coats can be applied after which the fiberglass chop is sprayed into the mold on top of the gelcoat and rolled out. Layers of fiberglass mat are then laid in to build thickness and wooden stringers are glassed in to strenghten the hull. It was an itchy job!

[imported_fastcar]

Wow, learned more about Gelcoats from this thread than in a lifetime. Excellent info!!

[gigondaz]

So, why are gelcoats used on boats and "automotive" paint used on cars?

Why isn`t car paint used on boats, or by the same token, gelcoat used on cars?

From my knowledge, on a brand new boat, the gel coat is not sprayed on, unlike cars.



When a fiberglass or carbon fiber part is being made, a MOLD is need.

The first layer to go into the mold (to line the mold) is the Gel-Coat, since GC is the outermost layer of a boat or carbon fiber items, or any gel-coated items.

The interior surface of the mold determines how smooth and shiny the finished product is.

Therefore, it is common for the mold`s interior surface to be micro-polished to varying degrees of smoothness and reflectivenes.

If the mftr wants the final product (boat, fiber glass items etc) to hv a highly refined, ultra smooth, super glossy look, he`ll need to perform extensive micro-polishing of the mold`s interior...and then apply that 1st layer of gel coat. It`s like a cake baking tray, and then lining that tray with butter etc !LOL!



So, when you look at a boat`s surface, how flat and refined the finish is, depends greatly on the quality of the mold.

Example: The mold used to make budget plastic, matte-look toolboxes does not need to be micro-polished.

The transparent, super clear HDPE or PET bottles used for shower gels wil require a mold that has been micro-polished.

[pushtiulk]

If I don`t want to compount a GC, can I only clay it and then wax it? And also, before wax, do I need to use some paintwork cleaning lotion, to prepare the surface for the wax?

[737-8dog]

Would sealants like upgp and optiseal work on a boat. Really enjoy these two products on my vehicle thanks to ease of use and durability. I use both on a friend`s corvette and would think they would work better than wax on a boat.

[SuperBee364]

Would sealants like upgp and optiseal work on a boat. Really enjoy these two products on my vehicle thanks to ease of use and durability. I use both on a friend`s corvette and would think they would work better than wax on a boat.

Gel coat is supposedly semi-porous, analogous to the older single stage paint on vehicles. Usually, sealants don`t do particularly well on semi-porous surfaces. It might be worth a shot, though. Give it a try just for grins and see how it goes.



--Supe (aka "737-7dog")

[737-8dog]

I received a response from ultima and optimum. Both said their sealant, upgp and opti-seal, work well on boats. Of course they want me to purchase more product. I am a new boat owner. Been detailing my cars for many years. Plan on washing and polishing with duragloss products. Will follow with collinite wax and several coats of upgp. Will post the results.

[ChevyFan]

Ok, i`m hoping that theres a boat expert reading this, or anyone that knows the answer. I applied an oxidation remover to my boat, and as soon as I started wiping it off I noticed the rag was turning green, the same color as my boat. So, does that mean that there was no gelcoat over the paint? Im totally confused. My first impression was thinkng like in terms of detailing a car... OH crap... I wet sanded through the clear coat or something along thoes lines. However theres no way that with two or three wipes of a rag that I went through the gelcoat on a boat. So I must be missing something with how fiberglass/gelcoat is put on... ANY ADVICE??? THANKS

[WCoaster]

Ok, i`m hoping that theres a boat expert reading this, or anyone that knows the answer. I applied an oxidation remover to my boat, and as soon as I started wiping it off I noticed the rag was turning green, the same color as my boat. So, does that mean that there was no gelcoat over the paint? Im totally confused. My first impression was thinkng like in terms of detailing a car... OH crap... I wet sanded through the clear coat or something along thoes lines. However theres no way that with two or three wipes of a rag that I went through the gelcoat on a boat. So I must be missing something with how fiberglass/gelcoat is put on... ANY ADVICE??? THANKS

Gelcoat can be confused with a clearcoat type paint finish. In fact gelcoat is actually a structural component of the boat. It is applied quite thick (20 Mil) and is tinted to the actual color of the boat. So what you are seeing is actually a stripping a layer of the gelcoat from the boat. This is not necessarily a bad thing as you are stripping the oxidation that has worked into the gelcoat.

[CEE DOG]

A LOT of great info and posts! Thanks for the info guys

[hacadacalopolis]

I have been doing alot of campers and rv`s and i cant tell you how agravating it is just to bring back the sheen of severly damaged gelcoat.



I wish there was an easier method of doing this, but restoring gelcoat takes labor intensive work that will wear you out. The best thing i have found to work best is the 3m Super Duty.



You cannot simply wash and wax these things that people are hoping you can do. I have done the method of feeding the gelcoat with wax (collinite 845) and it is just a waste of your wax. plus the buffer marks that will be left from staining. It is inevitable that you will have staining issues and possibly holograms/buffer trails.



I hate it so much, but a paying job beats that any day.