Gelcoat restoration

[Hermit Scott]

I have read and studied Mainsails gelcoat restoration thread. These maybe sound like stupid questions but I like to be crystal clear before I start something. These questions are sort of directed to mainsail but all help is gladly heard.
My boat is a 1979, I would say it is severely oxidized. IS there a level of oxidation that is too far gone that can't be restored by this wetsanding and polishing method? If there is, how do you know the gel coat is a lost cause. rub my hand over it and get white chalk on my hand.
Is restoring the gelcoat on the deck the same procedure for the hull?
When you talk about wet sanding, you say start at 600 for severe oxidation then work your way up to 1000, later in the thread you say go to 1200 then 1600.
On a 2x2 area, how long are you spending with each grit? Also are you sanding the whole boat with 600, then sanding the whole boat with 1000 ect. Or do you sand a 2x2 with 600 then the same 2x2 with 1000, 1200, 1600. Then move to the next 2x2 and start over at 600?
My boat looks yellowed from years of neglect. Do I need to FSR or off and on the topside also? If I am going to be doing a section at a time and then come back a week later and do another section, what stage do I need to stop at so I don't lose any progress by having the weather ruin what I have already done? Do I need to go all the way to the wax stage?
Concerning the FSR and off and on, how much do you estimate it should take for a 30' boat? I don't want to over or under do it.
There are some pics at www.myspace.com/sailboatspace

 

[Tim R.]

I will give it a shot

First of all Scott, you will learn a lot about this procedure as you go.

My boat is a 1979, I would say it is severely oxidized. IS there a level of oxidation that is too far gone that can't be restored by this wetsanding and polishing method?

Generally, no. It has more to do with gelcoat thickness than level of oxidation. Most boats have never had this done and yours really doesn't look that bad.

If there is, how do you know the gel coat is a lost cause. rub my hand over it and get white chalk on my hand.

Chalk does not indicate much. Boats will get chalky very quickly if neglected.

Is restoring the gelcoat on the deck the same procedure for the hull? Yes

When you talk about wet sanding, you say start at 600 for severe oxidation then work your way up to 1000, later in the thread you say go to 1200 then 1600.

Try this - 600, 800, 1000, 1200, 1600, then rubbing compound, etc

On a 2x2 area, how long are you spending with each grit? Not too long.

Maybe about 30 seconds with very little pressure

Also are you sanding the whole boat with 600, then sanding the whole boat with 1000 ect. Or do you sand a 2x2 with 600 then the same 2x2 with 1000, 1200, 1600. Then move to the next 2x2 and start over at 600?

Your choice

My boat looks yellowed from years of neglect. Do I need to FSR or off and on the topside also?

Sanding will remove any stain that FSR or On/Off would. And if you are referring to the topside as being above the gunwhale, that is considered the deck. The topsides are from the waterline to the gunwhale. There are those here that will flame you pretty badly for not knowing the terminology.

If I am going to be doing a section at a time and then come back a week later and do another section, what stage do I need to stop at so I don't lose any progress by having the weather ruin what I have already done?

Nothing. A week will not cause you to lose progress. A couple of months will though.

Do I need to go all the way to the wax stage? No.

Concerning the FSR and off and on, how much do you estimate it should take for a 30' boat? I don't want to over or under do it.

Don't need it.

Start on the transom and work slow until you perfect the technique. It is really not as complicated as you have made it.

 

[Kevin3447]

Try the compound first

Hi,
From the pix on myspace, your boat doesn't look too bad. I would try compounding a section first, before you start sanding. You want to remove the least amount of gelcoat possible. If you don't get the results you want, then sand it. I have a '79 that was chalky, and compounding then polishing put a nice shine on it.

Take mainesail's advice about the equipment - before I read his thread, we were using one of those cheapy orbitals. Our neighbor saw us, laughed, and lent us his Makita. We immediately threw the P.o.S. in the trash, and bought our own Makita 9227.

Good luck,
Kevin

 

[Hermit Scott]

yellow

Tim, thanks for the details. On the thread on Mainsail's disertation on gelcoat a guy says that his son restored his gelcoat but it turned out a beige color instead of bright white. I think the consensus was that it wasn't properly cleaned to remove the metals and tanning that the sea water deposited.
I guess if that was a problem, if I understand the theory correctly, you could use fsr at any point in the process before waxing.
Kevin, I am not going to even start until I get a Makita 9227. There is no substitute for good tools. Eveybody that does gelcoat restoration swears by it.

 

[Rob19574]

C-30

Scott -

I am in a similar situation with my '78 C30....oxidation is really bad and the gel coat lost any shine yrs ago. A good friend of mine did Mainsails method a few yrs back on his '88 powerboat and it came out like a show-room condition boat. I am not sure what grit papers he used but I know it was similar to what they have listed on this thread. You really cant mess up unless you do two things: 1- sand too hard and go right through the gel coat or 2- get swirl marks which you then need to just sand out with a higher grit. I just might do my boat if I could find the time.

Also - I was checking out your mySpace page pics - looks like you rebuilt your Yanmar....is it a YSM12 in there? I did the same on my boat, a YSM12 and painted it blue too! We probably are the only 2 Yanmars out there painted blue!

- Rob

 

[Tim R.]

Interesting

I had some rust stains caused by the vent on a propane locker. I keep my BBQ propane bottles in there. Anyway, I used the 3M superduty and they came right off. I guess it cannot hurt to go over the boat with On/Off before you sand.

I have heard of release wax getting ground into the gelcoat when sanding because it was not first removed properly with lacquer thinner.

 

[Hermit Scott]

Blue Yanmar

Rob My YSM 12 is still in a million pieces, I am waiting on some parts to arrive to my dealer from the distributor. I had it painted blue but the paint I used had to be baked on at 600 degrees. I didn't know that when I bought the paint or I wouldn't have bought it. I didn't want to tear down the transmission all the way so I went back and repainted everything cast iron color. The blue is way cooler. But I don't recommend bake on paint unless you tear everything down so you don't have to worry about temperature taking the hardness out of the roller bearings, gears and journal bearings.
I should have stuck with the blue, or bright red.

 

[Hermit Scott]

Rebuild

Rob, Since you have a 30' boat with a YSM 12 also, do you think it has enough power? Does it get you in and out of the slip ok, and will it get you up to hull speed?
I want to take my boat on a trip through the gulf to the Bahamas and stay there for a few months. Most people recommend a universal 25 but I didn't have the money to repower right now.
When you say c30 by that do you mean catalina 30? Have you taken it out into the atlantic? I don't know all the sail lingo yet. If so did you motor through any weather?
I was apauled by the coat of the parts! I am used to dealing with chevys, where a rebuilt 350 cost 650 with a core exchange. The parts alone are getting near $750 for my ysm.

 

[Tim R.]

Cheap parts

Scott, most marine diesels are just marinized tractor engines. My Universal is a Kubota and I can get most of the parts at the local kubota tractor dealer.

 

[Hermit Scott]

Yanmar

The consensus on this site seems to be that my YSM-12 will not make me happy in rough seas. After I get my boat finished, gel coat sanded and polished, motor in andbottom job, I am going to look for a 25 HP engine to rebuild. I am going to research and find a model like yours that I can get cheap parts for. Rebuild that in my shop and then swap them out. Universal 25's are said to drop right in my catalina 30. That is the recommended engine by a guy I trust on this site TonyB.
I just looked at your pics. IS that engine a universal 25? I guess that is one that I will look to buy later on. Are you happy with that engine? How does it run and how's the power?

 

[Hermit Scott]

link

Tim, How did you make your signiture at the bottom of your posts a link to your photo site? I tried to do it with my myspace page but it is not working for me.

 

[Allan R]

Try taking out the

www on your hyperlink

just enter it this way http://myspace.com/sailboatspace

 

[Tim R.]

I am not sure

It shouldn't be the www. I cut and pasted your link and it worked fine.

Phil?

As for the engine, mine is a Universal M25xp and it has plenty of power for your boat. Rather than rebuild one which can be expensive, it might be better to buy a dead one for all the marinized parts and bolt them up to a new Kubota block.

 

[Hermit Scott]

Testing

OK here's a test for the link

 

[Hermit Scott]

weird

IT would not allow me to take out the www. IT did not become a link until I added my name like you have. That was weird

 

[Stu Jackson]

Universal Engines

The M25 is 21 hp. The M25XP is 23 hp. Not a significant difference. The only "marinized" part is the heat exchanger, since ya just can't make a radiator work on a tractor engine in a sailboat. The HX simply mounts on the bracket at the aft end of the engine with two big hose clamps. The freshwater hoses from th manifold go there and the raw water inlet goes to the raw water pump then out through the muffler. Also, there's a tap from the freshwater pump back to the bottom of the thermostat housing for the line to the hot water heat exchanger. The M25 was in use on the C30s for years. We have one on our C34, a heavier boat, and it works just fine.

 

[Hermit Scott]

tractor

If I can find that engine from a tractor I would be very happy. I can build the HX no problem. I would like to see the inside of one and just copy that. IT's better than me trying to guess how many inches of tubing and what diameter. Is your HX all stainless or are the tubes inside stainless and the case bronze? Can you open up your HX, how do you clean inside?
So some tractors are made with just a forward, reverse and neutral gear system?
I plan on building a HX system for my YAnmar YSM12, because when I tore it down the ports to the head were so clogged only two had any flow at all.

 

[Stu Jackson]

It's a Kubota tractor engine married to a Hurth

transmission. The HX and tube are all bronze. Check out www.marinedieseldirect.com for more information. They even have blow up drawings of all the parts!