Gelcoat Removal

[Marshall Mahoney]

Looked at a "Gelplane" gelcoat remover -- over $2000 (like that's going to happen). Has anyone tried an electric planer to remove gelcoat?

[CaptPatrick]

Marshall,

Don't even try... Hand power planers are fitted with high speed straight steel blades, usually 2, that turn in a direction opposite & perpendicular to the direction of travel (like a barrel laying on the surface to be planed).

Gel Peel type cutters are more like a biscuit cutter with a circular blade turning parallel to the surface being planed, (like a table saw blade laying flat to the surface). The blade tips are carbide tipped and will stand the abuse of cutting fiberglass.

The planer blades will go dull almost instantly...

Br,

Patrick

[JP Dalik]

2K sounds cheap compared to the white suits and grinder dust associated with other methods. Not to mention the 2 month itch and white tears, boogers and ear junk....... Don't touch anything with that dust on your hands (so that means no drinkin.... cause drinkin leads to peein and.....................well you know where this is goin-OUCH!!)

Gel plane with vac attachment 2K no itch, no dust........sounds like a solid investment probably even shorten the time the whole job takes. In the end its only money the question is do you want to work smart or work hard. We've done a little of both on our never ending project and smart hurts a little more up front but in the end is faster then working harder than you have to.

Good Luck.

[John Jackson]

I took all of the crazed gelcoat off of the Hound (well, at least half) using a Festool Rotex vacuum system. I had a professional fiberglass guy do the flybridge and inside the cabin. It was a mother of a job. I tried the chemical remover, but it was too aggressive and made me nervous that it would ruin the fiberglass.

Seems to me that the only way to remove gelcoat is with a sander, time, skill and tender loving care. I used 60 grit paper for most of it and a vibrating/rotary sander, I believe 5 inch. Got much better at it as I went along.

The pro I worked with used an air powered rotary sander that was a lot more powerful than the Festool one I used. When I tried his, it was way too agressive for me to handle but of course the pro made it look easy. He did in two days what took me a month. He called the tools I had "cute."

How much gel coat are you removing and from where?

I did the bottom and it was a lot easier after the sandblaster beat it up and made it porous. Working around the lift strakes is the challenge there.

[mike ohlstein]

Looked at a "Gelplane" gelcoat remover -- over $2000 (like that's going to happen). Has anyone tried an electric planer to remove gelcoat?

Sounds like Suzi's getting some new kitchen cabinets....

[Marshall Mahoney]

Thanks for the advice. I found a cheaper type gelcoat remover -- called "Marineshaver -- about $600. I'm going to wait to see if it is absolutly necessary after I soda blast the bottom. I'll weigh individual blister/bottom repairs vs doing the whole thing once and for all. Targetting this Friday for blasting.

Suzie got new counter-tops -- close Mike.

[CaptPatrick]

Marshall,

After you soda blast all the bottom paint off, you'll find that sanding the exposed gelcoat down to parchment paper thin will be pretty easy with a DA & 80 grit disc. By not going all the way to fiberglass, you'll avoid getting a bad case of itch.

I've had the Gel Peel machine used a couple of times and it can create more work than it saves. You end up with a pretty rugged surface and lots of areas that just have to be sanded the old fashioned way. Then you still have to sand & re-fair the gross-o-moto gouges left by the peeler.

My suggestion is to save your money that might be spent on a piece of equipment that sounds better than it is & buy a couple of rolls of 80 grit discs for a tenth the price.

Br,

Patrick

[randall]

hey marshall...got nothing to add to patricks good advice...just wanted to say hi.......maybe we'll all be in port eades again soon......good luck with the boat....always the sentimental favorite

[Raybo Marine NY]

we did a blistered bottom of a 72' last year, tell the blaster to go heavier on it and most of them pop. Those that dont pop are easily popped with a small die grinder or even a counter skinker of they are not that wide.

then it was 2 days of sanding by electric da sanders and 80 grit, dont go any gritier or else it will actually work worse.

Went with some drywall spreaders which worked better then body filler spreaders and some underwater epoxy fairing.

For a 31', it would be a walk in the park compared to that 72 footer.
Get yourself a good fan and you wont even need a tyvek suit.

[BillinFI]

I just finished my 1962 25 Sport Convertible. There are extensive pictures in the discussion thread Proud New Owner on the 25bertram.com site. I sanded off the awlgrip over gelcoat down to leaving just enough of the original gelcoat to see the color (dark blue.) I used a Fein 6" sander/vac combo - great tool. My son did much of the original sanding with 60 grit and left lots of divits. I tried to clean them up before spraying on new gelcoat but there were still lots of whoop=de=dos. So I block sanded with 80 then 120 and sprayed again, block sanded again then a final coat of gelcoat. We use a trick method of 50% gelcoat from Cooks Composites and 50% Duratech High Gloss Clear. We cleaned the gun after two cups, using a primer gun and really lay it on. After there is a good coat, I block (meaning hand) sanded with 220, 320 then wet 400, 600, 800, 1,000, 1,200 then 1,500. Sand with the block parallel to the waterline in diagonal motion, never resanding the same spot. It is essentially longboarding. That's where I am now, I'll use 3M compound then Finesse It II to finish up the shine. You can already see how ugly I am in the gloss! In sum, doing a lumpy job of removing the gelcoat only dooms you to more follow-up work as the project continues. Good old sandpaper with a careful hand and a good machine (or block) is the shortest method after all is done, I think.

[Marshall Mahoney]

Last questions -- maybe.
1) Once I've sanded the hull to paper thin gelcoat, do I need to seal it with 100% solids epoxy followed by Interlux 2000/2001, or can I use Interlux 2000/2001 only?
2) Same question if I have exposed fiberglass fibers.

There seems to be 2 schools of thought.

--Marshall

[BillinFI]

If you are talking about the bottom, it depends on the condition. Major open areas should be spot repaired with epoxy. Once the substrate looks good and is sanded to 80 grit, then the Interprotect goes straight on. I have been hearing good things about a vinylester barrier coat that you may hear more about here. Put plenty on then the bottom paint. Mine looks pretty darn good after 3 beginning Interprotect coats with spot filling and sanding (using Interlux Watertitie filler) then a couple more Interprotect coats and finally Trilux 33 (white). Selection of bottom paint is a personal chopice, obviously.

If you are talking topsides, simply use the gelcoat directly on the substrate. Use can use gelcoat as a filler putty by making up gelcoat mixed with cabosil. Kick it and apply, sand out then repeat as many times as necessary. Then apply the finish gelcoat or if you must, the polyurethane paint following their system(Awlgrip, Imron, etc.) At least this is how I did it and it worked out pretty good (and I am an amateur.)

[CaptPatrick]

Marshall,

The Interlux 2000/2001 barrier coat is epoxy, & I'm pretty sure that it's 100% solids, so no pre-coat of regular epoxy is needed. That is, other than any necessary fairing or patching.

What makes the barrier coat more effective than just straight epoxy is that it's formulated with micro platelets of aluminum that, when applied, overlap one another to create a tougher more abrasive resistant surface.

An absolute minimum of 2 full coverage coats are required & this is a case where "more is better". The first coat of bottom paint must be applied within the specified re-coat time window. Basically, the first bottom paint coat should be applied while the last epoxy barrier coat is still curing. This will give the maximum bond between the two materials.

Use a different color of bottom paint than what you select as your visible color. This will act as an indicator coat that, when it starts showing through your preferred color, indicates that it's time to repaint the bottom. Use a hard non-ablative paint for the indicator coats, (2 coats prefered).

Br,

Patrick