Best filler product for topsides repair

[ronellis]

I need to repair some deep gouges on my topsides. I have used thickened West epoxy and MarineTex to do repairs on boats before, but I found both to be nearly unsandable. Since these repairs will be visible and covered with shiny new paint (probably Brightsides in white), I want to be able to easily sand them to perfection.

What non-epoxy filler products have you used that successfully repaired the gouge and were easy to sand?

Here's some of what I'm up against:

[img]http://img.photobucket.com/albums/v233/ ... 210085.jpg[/img]

[Oswego John]

Ron,

The purist powers that be and the board of directors at West Marine and West Systems would probably want to keelhaul me for saying this. I've had good results using plain old Bondo body filler on fibreglass and gelcoat.
If you have ever done any auto body work on fibreglass or metal, you know that the secret of a good finish is being able to sand or wet-n-dry the filler. Bondo works good for this use.

Good luck.
O J

[ronellis]

OJ,

Thanks for your reply.

I read somewhere (in the archives of this or another discussion board) that bondo could not stand up to the marine environment. Have you had a different experience?

Also, what do you mean by "wet-n-dry the filler"?

Thanks again.

[Oswego John]

Hi Ron,

Can't say for sure. I don't know what will happen if it should break down. All I can say is that I repaired my own Ty with it after storm damage in 1991 and it seems to be holding up okay. I can't seem to remember the exact spots that I fixed with it. It doesn't show

The boat had been used extensively in salt water, which I think would be harsher than sweet water.

Other than my own personal boat, I have used it dozens of times repairing other boat hulls, power and sail. I can't remember if I ever used Bondo below the water line. Maybe that's a consideration.

My suggestion is that if you have any doubts, keep looking for something else that is advertised for marine use. Hopefully, others will send in what they have used successfully.

Considering the cost and labor involved, don't experiment. There are dozens of marine products on the market. Check out the West catalogue.

Good luck,
O J

[Oswego John]

Hi Ron (again),

Sorry, I forgot to tell you what wet and dry is. I have a severe case of CRS.

Wet and dry is a waterproof sandpaper used in fine sanding and polishing applications. I usually buy mine in an auto supply. It is usually black in color.

It comes in agressive coarsnesses but is mostly used in progressively finer grades up to 600 and even finer. With the finer grades, it is possible to attain a looking glass, mirror finish. How do they say,"smoother than a baby's bottom".

I usually use wet and dry with a flexible rubber block holder. I dip the paper in a pail of water and wet sand the finish, hosing off frequently.

Good luck,
O J

[Steve Laume]

The Bondo is probably the easiest to work with and should hold fine. It looks like the damage you have is to the paint layer on the topsides. It would seem like you may be able to fair this in by feathering back the edges without any filler. If you no decide to go with an epoxy filler West System makes a filler material designed for sanding and fairing. I don't know the number off hand but you can find it in any of their information. I have never used it but I would imagine it would sand pretty easy, as that is what it was designed to do. A couple of other considerations. If this is damage to a painted area and someone ever decides to strip all the paint then your filler would have to be sanded off to achieve a fair surface. Bondo can be applied and drys to the point where it can be shaped and sanded in a matter of minuets. Epoxy would take a day or so to dry before you could proceed. Whatever you use, you will need to feather back the rough edges to get to good solid bonded material. Then get a rubber squeegee and apply a thin smooth layer to minimize sanding. A long flexible board will help keep the hull fair while sanding. Have fun, Steve.

[David van den Burgh]

I need to repair some deep gouges on my topsides. I have used thickened West epoxy...

Ron,

Which thickener did you use in your previous epoxy repairs? If you used something like colloidal silica, you can expect a tough time with the sanding. If you use a thickener designed for fairing, the job should be much simpler. I would try West System's Microlight 410 fairing compound for the pictured repair.

Just a thought, but perhaps you're already aware of this.

[ronellis]

Thanks Steve and David for your replies.

The picture doesn't show them well, but there are some deep gouges there that need filling.

I'm leaning toward the 3M Premium Marine Filler. It's a vinylester product. According to the info in the West Marine catalog it dries in 15 minutes and is easily sandable. Anyone have experience with it? Is it really easily sanded?

I'm pretty sure the Bondo would be fine, but with the amount of effort I'm going to put forth in prep and paint, spending a few extra dollars is probably cheap insurance.

I don't recall which thickener I used before in the West Epoxy, but I believe it was one that was advertised to be sandable. I was using 80 grit on my palm sander. The problem may have been that my sander is not up to the job of grinding back something as hard as epoxy.

Thanks again.

[marilou]

I have found that West 407 to be easy to sand. 410, as mentioned above, is also sands easily Getting the filler smooth, as possible, before it hardens makes the job go much faster.

For minor cosmetic repairs I like 3-M Acryl Marine Putty - 3M-05962. One part, comes in 21 oz. tube. Very easy to use and sand. No mixing so you don't have to rush your work. Around $17.00 at Jamestown Distributors. West also sells it.

[Len]

Which filler would give the best holding power in wood? (For screws that have been yanked out and left oversized holes)

[Oswego John]

Leonard,

I can't say which is the best filler for wood.

I have always had good luck using Wood-Tex and sometimes Durhams Rockhard Wood Putty.

O J

[Oswego John]

Getting the filler smooth, as possible, before it hardens makes the job go much faster.

marilou,

One of the tricks to get a smooth finish with little or no sanding is to apply the compound evenly to the surface being repaired and then laying a sheet of acetate over the compound and gently apply pressure to the entire surface, smoothing it out . Work from the inner application, working any excess compound toward the outside edges. Remove any excess before it hardens.

Clear acetate is like a sheet of plastic cling-wrap, only heavier gauge, thicker and stiffer. The filler won't adhere to the acetate. When the filler hardens off, remove the acetate. The finished surface, when done properly, will be as smooth as the surface of the acetate..

Clear acetate can be found in the auto body repair and refinishing section of most auto parts stores.

FWIW
O J

[marilou]

I agree. I have used standard Saran or plastic wrap with Gel Coat, and it does help promote a smooth finish and does not bond with the filler. Also, whenever possible use the slow harderner when using 2 part epoxy with fillers.