At the gelcoat stage - help needed!!!

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Patchaid is far better. Patchaid is a trade marked name, but its also used to refer to products like it generically. The issue with this type of product is that it has a relatively short shelf life when compared to styrene or MEK, so suppliers don't like to keep it in stock, but some do have it. Check places that sell gel coat and ask them about patching products, they may have a different name for the products they supply.

Cheers Ondarvr, I have to go buy more acetone this morning so I can carry on sanding the hull, while i'm in there I'll ask the question.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Well just as I thought, my supplier recommends Styrene Monomer additive, its all they keep in stock and they cant source MEK solvent or patchaid. ( in fact they have never heard of patchaid )
I really don't want to go against the advise given to me by YD and Ondarvr, But I may not have much option because even although I can source MEK solvent via ebay, My resin supplier can't gaurantee that this would be compatible with the gel they supply. They also said that the sprayable gel they sell will not need thinned that much and because of this the yellowing that is usually found with using styrene should not be an issue, is there any truth in this?

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

I have used styrene and acetone 50-50 mix for reduction.

Patch Aid is a CCP product http://www.ccponline.com/index.aspx .

MEK can be bought at Home Depot over here..I dont know if your hardware stores carry them..

You can use styrene..acetone..or MEK.

You thin it JUST enough to spray it . If you dont need to thin..then great .

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Thanks YD

I would love to use patchaid or MEK solvent but I think I will probably have to use the styrene and possibly acetone. Main reasons being availability and compatibility, I will keep my options open though for the time being as the gel wont be getting sprayed for another 2 weeks time ( can't wait ).

 

[proshadetree]

Re: At the gelcoat stage - help needed!!!

I have been reading everything on gel-coating for a year that I can find. Still seems like some mad scientist stuff to me. Two of the best giving advice on here. I will be watching progress on this one.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I have been reading everything on gel-coating for a year that I can find. Still seems like some mad scientist stuff to me. Two of the best giving advice on here. I will be watching progress on this one.

Couldn't agree more proshadetree, I feel priveladged to be getting so much info from the best in the trade.

" Still seems like some mad scientist stuff to me " I agree with this one too. I have been spending just a little time looking into the different thinners mentioned here, and it is way over my head, you really need a degree in chemistry to understand alot of this stuff.
Thats why I'm so glad theres people like YD and Ondarvr here that know their stuff and is willing to dumb it down for the likes of me.

 

[proshadetree]

Re: At the gelcoat stage - help needed!!!

Well when they get it dumb enough for you just dumb it up some more and explain it to me. I have an old sidewinder I need to get on when time permits.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Well when they get it dumb enough for you just dumb it up some more and explain it to me. I have an old sidewinder I need to get on when time permits.

Your brave, asking me to explain it !!
Lets see if I get good results, I will be surprised if I don't though with the amount of info supplied here.
(And if I get bad results . . . . . . . Do you know any one that wants to buy an upside down, badly gelled hull.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

*** DISASTER ***

MAJOR SETBACK

Everything was going great today, I managed to sand the gel on the other side, only a little more fairing work needed, ..........
THEN DISASTER STRUCK

For a couple of weeks I have been noticing a small dribble of water running down the hull every few days, but I automatically thought I had a small drip coming from the roof on my garage, i noticed it again today but it's not been raining here for days now, so I thought I would investigate.

I managed to pinpoint the location were the water originated from and when I pushed on this spot with my finger, water would seep out very slowly, the glass also felt a little spongy. I decided I had no option but to grind out the bad glass but I thought I could get away with a small repair untill I started grinding. I have now grinded out all the bad glass which has left me with a 1 foot by 1 inch hole in the glass.

To add to this problem, I dont think it will be a straight forward repair as there is no way I can get to the inside of the damaged area as it seems it is on an outer skin, there is really solid glass underneath but with a gap of about 1 inch. There was a puddle of water underneath the damaged area, this must have been some sort of water trap because the hull has been upside down in a heated garage for over 6 months. I am thinking it must have been damaged slightly before I owned the boat and water has been seeping in and the glass has been absorbing it over time. As you know I am no expert so any ideas / advice anyone ? I have managed to get all the water out by getting a hose in there connected to a small pump but some drying out time is now needed. The photos I have uploaded will explain this better.

here's the pics.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

And some more : -

A couple of questions regarding this "repair"

1. For this repair as it is not structural ( at least I don't think it is ) would csm do the trick or will I have to use a woven cloth at first?
2. Can this repair be done only from the outside as there is no access to the inside?
3. should I just abandon this project lol ?

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Grind/bevel..mohair ..glass .. fill and fair ..gel and finish..

Grind out 4" for taper on the repair area.. glass with mat + biax or woving..

You found an air void looking at the pics.. no biggie.

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Grind/bevel..mohair ..glass .. fill and fair ..gel and finish..

Grind out 4" for taper on the repair area.. glass with mat + biax or woving..

You found an air void looking at the pics.. no biggie.

YD.

I was hoping it would be something that simple. Cheers YD. All I have to do then is grind a little more for the taper. I will go get the stuff needed tomorrow and make a start on it. It shouldn't mess with the gel shoot date then hopefully.
So sigh of releif folks, we will still be good to shoot on the 22nd.

I'm glad I stumbled upon this just now and not when the gelcoat was applied.

Cheers again YD

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Yes..a 4" taper..then fill/glass .

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I started work on the repair today, I managed to get 3 layers of woven cloth (360g) on there with still enough space left for a couple of layers of csm. I will get the csm on tomorrow and then fill the following day. So its all going well so far.

It may be a little early to ask this question but I just want to make sure I have all supplies in plenty of time.

When going through the grits 400 -1200g. In what way is the best finish achieved : - hand/block sanding or power sanding?

There is a few areas I know I will have to hand/block sand as the DA sander can't reach certain areas so should I just stock up on sanding sheets and not bother with discs?

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Block sanding is the best.

After your block with 320 you dont need a block anymore..your not fairing the gel after that point..just getting out scratches.

Unless you want a Superb mirror..then block it out ( You will flip your block pad on the ground so many times just from suction its not funny ) .

YD.

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

Block sanding is the best.

After your block with 320 you dont need a block anymore..your not fairing the gel after that point..just getting out scratches.

Unless you want a Superb mirror..then block it out ( You will flip your block pad on the ground so many times just from suction its not funny ) .

YD.

Cheers YD. I take it you mean after the 320 I should ditch the block and just sand by hand ?

 

[Yacht Dr.]

Re: At the gelcoat stage - help needed!!!

Yup ..

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

That's a relief, I thought I was going to have to spend a fortune on hook & loop's.
Thanks YD

 

[stan thomison]

Re: At the gelcoat stage - help needed!!!

I use a Wagner 3 stage hvlp to finish guitars and works well. You can find them fairly cheap. Might ask if it will work for this. When talking gel coat is that basically a clear coat? Not lacquer like I use but work same way?

 

[morebass 17]

Re: At the gelcoat stage - help needed!!!

I messed about with the spray gun with some international prekote. I thinned it down with acetone just for practicing. I think I will have to spend some more time practicing though because the paint didn't seem to atomise as well as it should, but I think this was due to the air inlet to the gun was not adjusted correctly , I will practise again without thinning the paint to resemble what the gel will be like. and i will also pay closer attention to the air inlet adjustment ( i obviously had it set too low, but by the time I realized this I had run out of paint.

I mixed up 1 quart of paint and I was surprised at how quick the pot emptied, so I am pretty sure I will be able to apply 2 quarts of gel in one go.

One thing that worries me though is once I finished messing about I flushed the gun with acetone THEN water. I realize now I got this the wrong way about, What is the consequences of doing this? will the water start to rust the inside of the gun? I wont be able to flush the gun with acetone untill monday because I use the compressor in my work and wont be back untill monday.

Hopefully I've not wrecked it.

Regarding the boat itself - it's a slow process but i'm now nearly finnished repairing the damage (another layer of filler needed) and just a little more fairing work to do to the rest of the boat , then i'm good to go.