sanding and preping for paint

[ElkySS]

So I am restoring a 1969 Venture 24 that I recently purchased. I have started sanding off the bottom paint and plan to do the whole thing in top side paint since it will be on a trailer and not left in the water. Sanding the top side has gone well but the bottom is giving me fits. The filler is cracked so I am having to take it all off. I tried using a Dremel to just widen the cracked areas but then quarter sized chips of old filler started coming off. I am using a Dewalt disk sander (not an orbital sander) to take it off but it is still pretty slow going. Is there a faster way to remove it or is it normal for it to be this slow? Also, once I get the old filler off how quickly do I need to put new filler on the fiberglass? Can/should I sand the whole bottom then fill it in or do a little then fill it back in and move to the next spot? Here are some pics if it helps any and thank you for any help you can provide. its my first time so I am learning as I go.

Bow just after power washing
https://goo.gl/photos/7n8zZzN5Tc8pxuKq7

bow after sanding. still needs a bit of clean up work and wiped down really good.
https://goo.gl/photos/ZdQhoFVDNarsUxfF8

part of the cabin after sanding. Should I take off the rest of the paint even if it feels smooth?
https://goo.gl/photos/DBWhWWALFLP6UMM88

couldnt get the img tags to sork for some reason

[Don T]

Hello,
Not sure what you mean by "filler" but it looks like you are sanding through the gel coat. Not sure if that's the best way to go about it.

Just questioning the methodology........

[kadet]

Soda Blasting

[ElkySS]

The pinkish bondo looking stuff. It is cracked all the way down to the fiberglass. The fiberglas is in good shape. Where the crack is at i can put a small screwdriver in it and a chunk of it will chip off where it is seperated from the fiberglass. My understanding was to remove it all and coat it with some evercoat formula 27 http://www.westmarine.com/buy/evercoat- ... 20_005_005 then paint. Is this not what should be done? I thought about renting a soda blaster or using walnut shells but havent looked much into it. Would that be a better way?

[topcat0399]

I agree with Don T; it looks like you are taking the hull down to bare glass by removing all of the gelcoat.

We haven't painted our hull yet but we intend to remove only all (or most) of the paint that is on top of the gelcoat.
And then we will fair out dings and crevasses in the gel coat to fair the bottom and hull sides.
Then we will prime and paint.

What you are calling "filler" I believe is gelcoat. If the gelcoat is cracked and falling out only address
those areas with filler or glass work if needed.

You can remove all of the gelcoat I suppose but I don't think it necessary.

[ElkySS]

There are 3 layers on top of the glass. A thin green layer that i think is gelcoat then a pinkish layer that is quite a bit thicker. Then paint. Since the cracks go all the way to the glass (but not into the class) then go between the glass and the green layer (alowing me to chip it off, do i not need to remove it all? Would sanding off the paint and skiming it with filler work? Even once i take off the paint the cracks are still there and can be pulled off.

[ElkySS]

There is a high lucky hood that i am doing it wrong. Here are a couple of other pics that might help better describe what i am seeing.

A chip that i pulled off with my fingernail. You can see the glass because the green layer has seperated from it.
https://goo.gl/photos/hu7F5rdjXY82yrMn8

This shows some of the cracks, all the layres of paint and the glass.
https://goo.gl/photos/5qAUWmyCW8Yp5DGN8

[Herschel]

Not at all sure this is what you need. Like others, it is a little hard to know what those layers are. But, that said, if you really want/need to take a surface down to a lower level and a sander is not doing the trick, I have found that a grinder will definitely get the job done. You just have to be careful because a grinder will take it down fast. I recently wanted to strengthen and fill some surface cracks in the top layer of fiberglass in the interior hull/bottom of my dinghy with more fiberglass cloth and West System epoxy. Consequently, I had to get all the old paint off for a good adhesion to the fiberglass hull. Sander was too slow; the grinder got it done. Just had to be careful.

[topcat0399]

Oh yeah. Seeing it that close, I would be taking a grinder with
something like a 120 grit flap wheel to that.

You can get pretty skilled with a grinder and fair the surface so
that it needs little further sanding.
I use flap wheels until they literally fall apart,
adjust technique with the wear.

Careful though, the grinder can quickly become the boat eater.

[ElkySS]

So if/when i get it down so the cracks and loose bits are gone do i need to then just use some of that formula 27 to cover the glass? How quickly do i need to do that? Do the who bottom then cover or area by area?

[topcat0399]

Sure you could use something like Evercoat 27 to fill SMALL divits, pinholes, gouges and to go over rough spots.
You just shouldn't use it to fill large deep areas or broad deep fills. It will just crack and fall out. You should do glass work on those. Evercoat 27 is a fairing compound that is to be used THIN - most that you apply you sand back off again.

After grinding/sanding you do not need to cover it immediately - you just have to make sure it is clean and dry when you do apply more products. I wouldn't have a problem with grinding/sanding the entire hull before going to the next step.

There is no one right answer or approach for everyone. Keep at her my man - I've been in process of restoring our old wreck while sailing for 5 years now and its all coming together. Painting the hull is almost last on the list.

[Herschel]

So if/when i get it down so the cracks and loose bits are gone do i need to then just use some of that formula 27 to cover the glass?

I am not familiar with Formula 27. I do have experience with West System epoxy both for big jobs and small jobs. The repair kit that West Systems sells for small jobs has fillers that you can add to the epoxy for larger cracks.

[ElkySS]

Sure you could use something like Evercoat 27 to fill SMALL divits, pinholes, gouges and to go over rough spots.
You just shouldn't use it to fill large deep areas or broad deep fills. It will just crack and fall out. You should do glass work on those.

First time doing this stuff so when you say glass work what are yiu refering to? The glass is in good shape so i assume that refers to some kind of covering before paint.

[Russ]

Woah woah woah!!

That looks like you are sanding right through the gelcoat. If you see dark fiberglass, you've gone too far. The layer after the bottom paint is fiberglass gelcoat.


Was the deck of your boat painted before? It may have been painted. Hard to tell.

[ElkySS]

Im pretty sure somebody painted it and did a crap job of it. I am trying to fix it all but since everything on the bottom has seperated from the glass I was aggressively sanding. I can chip at it with my fingernail and chunks will come away and leave raw glass. How should i fix it if not to sand it off?