Flowcoat Color Matching

[svranjic]

Yesterday I decided to get underneith the boat and fix the dodgie repair job undertaken by the previous owner.

Previous owner had used gelcoat repair kit to fix scrapes / scratches on the keel and various other parts of the hull. Nothing major but he didnt do a very good job and the stuff has turned yellow over time in the water. Obviously the boat has been beached often due to wearing of the keel, other damage seemed to be from trailer retrieval.

So I sanded back all areas where the putty had been used right back to the original paintwork. Cleaned with acetone, then when out and baught myself a tin of white flowcoat + some MEKP.

Came home, applied flowcoat with brush and allowed to dry. Lightly wet sanded it today to make it smooth.

However the color match is pretty far off, My hull is a sort of a white / grayish. Should I have mixed a bit of black pigment into the flowcoat? or am I wasting my time trying to get the color to match? After all it is belowb the water I guess

[sharkcat one]

HI SVRANJIC,

Flowcoat is only used for painting the inside of your boat , not the outside. you will need to use gelcoat with some pigment to match the colour . Flowcoat will not withstand the outside conditions , may crack and peel . Flowcoat has no uv stablizers and will turn bright yellow with time. You should be able to buy some gelcoat from your nearest boat repairer or contact FGI or Marineware and they will sell you the right gear.

Cheers.

[svranjic]

Gday sharkcat one

Im a bit confused. I only put the flowcoat on because of a couple of threads I read on this forum suggesting to do so....

http://www.ausfish.com.au/vforum/sho...light=flowcoat

And

http://www.ausfish.com.au/vforum/sho...t+grand+marlin


I really hope I dont need to sand the whole lot back again!!!

[Grand_Marlin]

I certainly hope I am not wrong, or I have about 5000 boats to re-do on Sharkcat 1's advice


Flowcoat will be fine for what you have done.

The bright yellow effect he is talking about is rather exagerated.
The UV will take the bright white appearance out over time, which is exactly what you are after - re: colour matching.

It sounds like you have it under control.

Cheers

Pete

[svranjic]

Cheers for that Grand_Marlin

So there is no need to try and add color pigment to the flowcoat in order to get a color match? Simply leave the bright white flowcoat as it is now and the UV will slowly dull the color down until it matches the rest of the boat?

Is this what would have been done if I had it proffessionally looked at? I hate to think how much they would have wanted

[sharkcat one]

Hi Guys,

Ok I may have exagerated a bit on the bright yellow , but it will change colour.

Grand Marlin I understand why boat repairers use flowcoat on repairs, it's because it is easier to sand and you don't have the stickyness of gelcoat.
There are about 3 ways to get rid of the stickyness out of a gelcoat repairs
1-- use a material called patch aid or patch booster at about 10 to 20%
2-- use a material called wax'n'styrene at about 6 to 10% ( only use this method if you know what you are doing )
3-- use straight gelcoat and when it starts to gel, spray PVA out of a gun onto
the repair , this will form a skin on the repair and you just sand through it.

I am a firm believer when repairing a boat you use the same material that the boat is made from. So many times I see a boat owner with a boat which has had a repair done about 3+ years ago which the repairer has used 2-pac on the gelcoated boat hull for the repair. And the repair is peeling off , I feel sorry for the boat owner because he has paid out so much money for the repair not to last.
A repair sould last just as long as the life of the boat. If the top coat of a boat is 2-pac then repair it in 2-pac, gelcoat hull -- gelcoat repair, flowcoat hull --- flowcoat repair, epoxy hull --- epoxy repair and so on . Gelcoat has a life of about 25+ years, flowcoat 10+ years, 2-pac 7 years, this is why you should repair your boat in the same material as it is built.

This is NOT a shot at Grand Marlin I have heard alot of positive feed back from boat owners who's boats he has repaired and I believe he does an excellent job.

This reply is to help boat owners make an informed decision about the repair being done on their boat because there is alot of doggy repair people out there willing to tell you anything to take your money.

Also to the boat owner when you are getting your quote done make sure the boat repairer does not use car bog or pink nikki in the repair as to much of this product will absorb water and crack over time. they should use materials like
pro-bond or vinyl ester bog or vinyl ester faring putty or locker bog etc.

To the person who started this thread , there is no need to redo the repair on your boat if it lasts 10+ years excellent , if not just repair it a different way.


To the people who are repairing gelcoated hulls & decks with 2-pac , STOP doing it , it is giving the rest of us a bad name. If you don't know how to do a gelcoat repair without getting a coffee stain ring or hallow be man enough to say that you cannot do this and refer the owner to someone that can.

Well that's my two cents worth.
cheers

[svranjic]

The flowcoat that I painted on still looks crap though!!!

Looks like a backyard job........

[Grand_Marlin]

G'day Sharkcat,

I agree with not using the 2 pac gelcoat repair putties for this type of work.

The gelcoat / flowcoat debate is not an issue for the type of repairs I do.
Talk to me about repairs on trailer boats, then talk to me about under water applications for permanently moored boats, then I will engage in debate over gelcoat with wax in styrene vs flowcoat.

Both gelcoat and flowcoat will change colour.

The time frames you give for life expectancy of gelcoat, sorry, I don't agree with.

If I had any doubts over my repair methods & products I wouldn't do them.
I have both products in stock and use each one when and where it is needed.

Svranjic,

There are certain methods I use for getting the best out of repairs.
Yes, you get what you pay for.

Take a look at the before & after pics of the repairs to this dash.
Same approach as I would use for your boat.

Cheers

Pete

[svranjic]

Looks fantastic Grand_Marlin

Tell us how you did it

I guess my question is if you were repairing the hull and keel on my boat, would you have used the stock white flowcoat and left the flowcoat to slowly dull in color over time - Or would you have mixed pigment into the flowcoat to make a closer match to the color of my hull?

Eventually I am going to get the boat off the trailer and onto stand so I can properly fix all scraped etc underneith hull and on keel. Currently the rollers stop me from doing it all.

Cheers

[BM]

Svranjic,

To answer your original question mate, colour pigments are available to mix the flowcoat to the required colour or close to it.

If you were to speak with every boat repairer around the country and ask them how would they "recoat" the surface of a boat you will find a tiny percentage who would actually spray the boat in flowcoat/gelcoat. The rest use 2 pack paint.

This debate has occured for a while on the down south forum too..

[TJ Bear]

When repairing any composite the place to start is to replace like for like. This includes the laminate removed, resin system used, core replaced. This is not my standard it is the standard for the Australian Composite Institute, Loyds and USLC.

Sorry Grand Marlin but the correct way to repair a gel coat repair is to use gel coat not flow coat. You may at times be able to get an acceptable result using flow coat on a white hull but it is still not the correct way to do it.

Personally I don't even like using patch aid or wax and styrene however at Riv we do as we need to get on to the repair quickly and patch aid facilitates a quicker process. If you spray your gel coat repair and give it time to harden up the tacky feel will go in about 24hrs.

As for below the waterline on a moored boat where the repair is going to be antifouled over I can't see any difference. Do you know what flow coat is made from? How do you repair a blue slab side hull with flow coat? The only way I have repaired slab sided colour hulls and I have done a few is to get the original colour gel coat from the manafacturer if its a new boat or use tint cards to match colours and tint the gel myself on older faded hulls.

[TJ Bear]

BM when it comes to refinishing an entire hull you could do it in gel coat but would be a huge job to do it right and cost a fortune in labour to fair it up as gel coat is bloody hard. Most economical way to do it is definatly 2 pack. At Riv all our boats are gel coated white and 2 packed the colour the customer wants, this is for boot stripes or slab side colour, you will find all big boat builders do the same. All composite super yachts are 2 packed. If I was rebuilding an old boat I would 2 -pack as the thought of doing it in gel coat gives me nightmares of weeks on a torture board looking at a hull covered in guide coat. This is however different to a repair on a reasonably small area not requiring the entire hull to be re finished. A repair I would always use like for like.

[svranjic]

Seems I need to by some black pigment and try to tint the white flowcoat to make it a little more gray.

Sigh Its going to be a total bitch sanding this back (again).

Probably not as bad as sanding back the gelcoat repair putty.....

To be honest it doesnt really bother me what I use to repair it, as long as it will prevent water leakage and be unnoticeable. I guess everyone is different and will use different methods weather it be 2 pac or gelcoat or flowcoat.

Flowcoat seems pretty easy to use, just trying to match the color which is the annoying part.

Work on the boat continues......

[cormorant]

I was always told that flowcoat is just gelcoat with styrene monomer and wax in it so it will air dry????? Probably a simplistic expaination?

How much harder is gelcoat compared to flowcoat?

A lot od decks on 20year old boats were done in that baby poo brown colour as back there wasn't a UV stabilised geyl coat avaliable and the white colours would go yellow brown anyway.

Should also say that a lot of people don't realise that gelcoat is not 100% waterproof and they is why antifouled boats use a barrier coat underneath them to prevent osmosis. New gelcoats are better than 20 year old stuff.

Lots of myths with get=l coats and flowcoats

[Grand_Marlin]

Sorry Grand Marlin but the correct way to repair a gel coat repair is to use gel coat not flow coat. You may at times be able to get an acceptable result using flow coat on a white hull but it is still not the correct way to do it.

Au contraire Mr. Bear.

The products mentioned have such subtle differences (i.e. fillers) that when used for minor repair work the difference in performance is negligible.

There is plenty of literature around to support what I do, there is plenty of literature around to support what you do, and there is plenty of literature around to support a gelcoat build up with a flowcoat topping that meets us in the middle.

The key to repairs is preventing water infiltration to the FRP Matrix, is it not?

Maybe, just maybe, I have developed a technique for ground up flowcoat repairs that works.

Cheers

Pete