Nauticat 52 Refit

[redsky49]

Minaret,
You stated earlier in this thread:

"In this pic there's a repair that's just been shot with color matched gel under the piece of blue tape. It's still wet. When it's been wet sanded and polished it'll look like new again. Gelcoat is more work to maintain, but at least it can be maintained, unlike paint. I suppose that's misleading, I shoot loads of paint blends too, but that is not really for the layman.* I can show you how to shoot gelcoat blends like this without even using a gun or a compressor (compressor - Cruisers & Sailing Forums - Discussions about Compressor). Can be done anywhere, no special tools required."

Have you posted this method anywhere? I have some gelcoat repairs that are needed on my 1981 Bristol that I would like to attempt this summer. It looks like one of the prior owners was too aggressive with the compounding and now the black undercoating is starting to show through.

Thanks. I appreciate all your contributions to this community.

[Richard5]

Originally Posted by redsky49

Thanks. I appreciate all your contributions to this community.

I 2nd the sentiment.

[minaret]

Originally Posted by redsky49

Minaret,
You stated earlier in this thread:

"In this pic there's a repair that's just been shot with color matched gel under the piece of blue tape. It's still wet. When it's been wet sanded and polished it'll look like new again. Gelcoat is more work to maintain, but at least it can be maintained, unlike paint. I suppose that's misleading, I shoot loads of paint blends too, but that is not really for the layman.* I can show you how to shoot gelcoat blends like this without even using a gun or a compressor (compressor - Cruisers & Sailing Forums - Discussions about Compressor). Can be done anywhere, no special tools required."

Have you posted this method anywhere? I have some gelcoat repairs that are needed on my 1981 Bristol that I would like to attempt this summer. It looks like one of the prior owners was too aggressive with the compounding and now the black undercoating is starting to show through.

Thanks. I appreciate all your contributions to this community.

Lets start by assuming you already have a good color match. All you need is the gelcoat, a selection of sandpaper, a buffer and compound, a heat gun, and a box of Preval's aboard your boat to do your own repairs. Lets also assume that the repair itself is done so we're only talking gelcoat application here.
You prep sand the area around the repair with 400 dry, very thoroughly. If you leave the slightest hint of gloss your repair will halo. Mask off lightly, 2' plus hatches or windows is fine as overspray will be minimal. Acetone wipe clean. Then pour a couple of ounces of gel in the Preval pot and carefully catalyze it. I like to reduce with about 10% MEK to increase flow and make it shoot easier. Be sure not to use surface seal or patch booster, just gel. Get out your heat gun and heat the Preval charger unit carefully until warm to the touch. Shake well first. This will give you much better pressure. Then shoot a coat of gel over the repair and about 1" onto the existing gel. Wait 15-30 minutes until quite tacky, cleaning your pot while waiting. Mix another little batch and shoot a second coat that goes 2-3" onto the original gel. Allow it to gel again, and mix a third small batch. This time add surface seal. Shoot it 4-6" out onto the original. Obviously for very small repairs you can keep it smaller. You can shoot up to tape for a hard edge on radii, or anywhere else it's appropriate. Every time the charger unit gets cold in your hand pause to heat it up. You get way better results and longer spraying time out of a charger unit like this. Don't be an idiot and blow yourself up! On very large repairs, or in cases where I am for whatever reason concerned about blowing through, I often do four coats. I wouldn't use a Preval for repairs bigger than a foot or two in diameter, but for the vast majority of small repairs its perfectly sufficient. You don't get the greatest finish but you are polishing it anyway. I like to blend starting with 800 wet for small stuff, finish with 1000-1500, compound with 3M, poly wax. I also use more high end expensive versions of the Preval for some stuff, but for the layman with a gelcoat boat I think it's hard to beat a can of good gel and a box of Preval's. Oh, don't forget to pull the little filter off the intake tube for shooting gel, it's too fine.




Preval Spray Gun, Power Unit and Container - Amazon.com

[minaret]

This boat spent some days on the beach in a hurricane. She was "fixed" and then sold. Passed survey twice since. The whole starboard side is destroyed, could be a total loss. Won't know for sure till its peeled. This is what hidden damage can be like. Pacific Seacraft.

[minaret]

The chalked areas hammer sounded very poorly. About 40% of stbd hull and 30% of port hull.

[minaret]

Solid hull lam completely destroyed, shattered right through with severe delam. She's been sailing like this for awhile now. Serious oil canning too.

[minaret]

That's not good!

[minaret]

Really not good! Massive areas of shattered glass and full delam. It'll be a big job! If its worth doing...

[Exile]

Originally Posted by minaret

Lets start by assuming you already have a good color match. All you need is the gelcoat, a selection of sandpaper, a buffer and compound, a heat gun, and a box of Preval's aboard your boat to do your own repairs. Lets also assume that the repair itself is done so we're only talking gelcoat application here.
You prep sand the area around the repair with 400 dry, very thoroughly. If you leave the slightest hint of gloss your repair will halo. Mask off lightly, 2' plus hatches or windows is fine as overspray will be minimal. Acetone wipe clean. Then pour a couple of ounces of gel in the Preval pot and carefully catalyze it. I like to reduce with about 10% MEK to increase flow and make it shoot easier. Be sure not to use surface seal or patch booster, just gel. Get out your heat gun and heat the Preval charger unit carefully until warm to the touch. Shake well first. This will give you much better pressure. Then shoot a coat of gel over the repair and about 1" onto the existing gel. Wait 15-30 minutes until quite tacky, cleaning your pot while waiting. Mix another little batch and shoot a second coat that goes 2-3" onto the original gel. Allow it to gel again, and mix a third small batch. This time add surface seal. Shoot it 4-6" out onto the original. Obviously for very small repairs you can keep it smaller. You can shoot up to tape for a hard edge on radii, or anywhere else it's appropriate. Every time the charger unit gets cold in your hand pause to heat it up. You get way better results and longer spraying time out of a charger unit like this. Don't be an idiot and blow yourself up! On very large repairs, or in cases where I am for whatever reason concerned about blowing through, I often do four coats. I wouldn't use a Preval for repairs bigger than a foot or two in diameter, but for the vast majority of small repairs its perfectly sufficient. You don't get the greatest finish but you are polishing it anyway. I like to blend starting with 800 wet for small stuff, finish with 1000-1500, compound with 3M, poly wax. I also use more high end expensive versions of the Preval for some stuff, but for the layman with a gelcoat boat I think it's hard to beat a can of good gel and a box of Preval's. Oh, don't forget to pull the little filter off the intake tube for shooting gel, it's too fine.




Preval Spray Gun, Power Unit and Container - Amazon.com

Real valuable guidance here, Minaret, thanks. I've got it bookmarked! I take it that, for larger areas, the sprayer is preferred over brushing primarily because it saves on sanding time? Or is there an aesthetic difference b'twn the two methods with the finished product?

Also, and just to review since I know you've hit on this before, the more common issue for my boat & probably others are small but often deep dings in the deck from dropping stuff. It's usually in the non-skid which I know has limited repair options. In my case, there is often black laminate showing so the main concern is preventing any water infiltration. Poly filler finished off with gel-coat? What about gel-paste to help fill smaller gaps?

[Exile]

Originally Posted by minaret

Really not good! Massive areas of shattered glass and full delam. It'll be a big job! If its worth doing...

I had (incorrectly) assumed that PS had solid hulls with no coring. We're looking at balsa or ply coring here, right?

[minaret]

Originally Posted by Exile

Real valuable guidance here, Minaret, thanks. I've got it bookmarked! I take it that, for larger areas, the sprayer is preferred over brushing primarily because it saves on sanding time? Or is there an aesthetic difference b'twn the two methods with the finished product?

Also, and just to review since I know you've hit on this before, the more common issue for my boat & probably others are small but often deep dings in the deck from dropping stuff. It's usually in the non-skid which I know has limited repair options. In my case, there is often black laminate showing so the main concern is preventing any water infiltration. Poly filler finished off with gel-coat? What about gel-paste to help fill smaller gaps?

Spraying reduces more than just sanding time. Brush marks and imperfections in brushed gel often require you to sand off the majority of what you put on. You really want to be leaving gel of a similar thickness as the original, usually 16-24 mils (quite thick). This means you must brush on several extra coats, which makes the repair larger and harder to block out fair. It's a can of worms, really. I would never brush a blend repair, ie one that must be blended into original gel on all sides.

Non-skid is a whole different can of worms. The method used depends entirely on the type of skid. A practical seal is quickly achieved in many cases by simply dabbing on a little color matched gel with something like a match stick, but in most cases this is not a cosmetic fix. Molded in skid is the most difficult thing I work on. I could spend several pages discussing methods of repair for it, and in the past I have on other threads. Gel paste is a waste of time. So is bondo. Flex molds can be made to work in many cases, but they are a PITA and definitely not for the layman. The method I most often use is also advanced and requires special equipment and techniques, also very much not for the layman. If you have molded in skid, seal any dings by dabbing and get a pro repair from someone who can show you an example of their results. Or, much better, do what I often convince customers to do. Grind off the molded skid and go with Griptex. This is relatively easy for the layman to repair, durable, looks great, more comfortable to lay on than molded, etc. etc. I can usually do a whole deck this way in less time than it takes to do a pro 1' by 1' repair in molded skid that is totally invisible.

[minaret]

Originally Posted by Exile

I had (incorrectly) assumed that PS had solid hulls with no coring. We're looking at balsa or ply coring here, right?

Nope, your right. That's solid glass. Just so shattered it barely looks like glass anymore.

[cpa]

Originally Posted by minaret

Nope, your right. That's solid glass. Just so shattered it barely looks like glass anymore.

Yikes, that is some scary stuff.

[europaflyer]

Originally Posted by minaret

Really not good! Massive areas of shattered glass and full delam. It'll be a big job! If its worth doing...

Is this a resin quality issue? Would it have held itself together is they had used epoxy or really top quality poly?


Loving the thread BTW!

[minaret]

Originally Posted by europaflyer

Is this a resin quality issue? Would it have held itself together is they had used epoxy or really top quality poly?


Loving the thread BTW!

Don't think so, though it hasn't been peeled yet. We'll know more when the coatings come off.




Thanks, glad you enjoyed.