How to fill a big divot in a plank?

[Jeff Kelety]

Hi all -

Well, of course only after I get three nice coats of topside paint on does it rain, thereby exposing a previously filled divot in a plank that I thought I had managed to seal. It would seem that I now need to dig out the existing bondo, etc (not placed there by me!) and do a permanent fix.

This is a couple of inch long by half inch puttied area around one of the counter-sunk bolts that secure the starboard chainplate. The paint around this area has started to bubble and flake. (Didn't do it, naturally, on the first two coats. Waited till I was all done!).

So the question is this: what is the best method of permanently and properly repairing a divot like this? More gouge? Epoxy in some wood? I presume I need to keep the chainplate bolt accessible with some sort of removable filler. But it looks like wood around the countersink has splintered and is not secured to the rest of the plank. This must be why much of it has started to lift.

Any thoughts here, gents?

Thanks,
Jeff

[ 06-18-2002, 10:29 PM: Message edited by: Jeff Kelety ]

[Noah]

I gotta say that I really like the West System 410 Microlight filler. It is very easy to sand, and does the job pretty well. I made a really sexy rudder this winter, and used the 410 to fair the thing. My friends that race Melges's and J 109's are jealous of what I put together.

Good luck.

Noah

[Paul Scheuer]

Chainplate - Not exactly a decorative item. One of its fasteners , not exactly an embellishment. Not a job for bondo (IMHO), or even wood filled imitation bondo. I think this situation calls for all the virtues of real wood, (compressable, paintable, etc.). I'd be thankful I found it before anything serious happened. I'd also be thinking about a new plank section.

[JimD]

I haven't that much experience with this issue, but I would lean toward what Paul says about new wood. But if you decide on epoxy filling, use as strong a filler as you can get, maybe this, copied from West System's website:

404 High-Density Filler
404 High-Density filler is a thickening additive developed for maximum physical properties in hardware bonding where high-cyclic loads are anticipated. It can also be used for filleting and gap filling where maximum strength is necessary. Color: off-white.

[RGM]

Forget the filler, of any sort. Figure out how big of a graving piece you need to fab and let in, plus a little extra for good measure. Fab a template that represents your graving piece (for router use), get set up with a router, reasonably fresh straight bit, the appropriate template guide (bushing) and go to town. Make cut deep enough to hit good wood. Get some suitable stock for your graving piece, same as your planks is best. Mill it so it's about 1/8" thicker than your hole is deep. Fasten or clamp the same template onto the graving piece stock. Grab hold of that same router set-up, lighten up the depth of cut so it's about 1/32" to 1/16". Make a shallow cut onto the new stock with your template and router. Remove the template, go to a bandsaw (jigsaw with decent blade will work), set the saw blade at about a 2 degree bevel. Using the outer edge of the shallow cut that you previously made with the router as the cutting line cut out the graving piece with a slight under bevel. Fit and adjust as necessary into the recess you cut in your plank. Glue, screw and bung the graving piece into place. Remember how the graving piece was 1/8" thicker than the whole was deep? This is where you fair the whole mess down so it marries up to the original plank surface real nice and hopefully with the under bevel and tight (slightly driven) fit you won't have any unsightly gaps. Drill a new and improved hole for your chain plate fastener. It's a great way to impress your friends and neighbors. You can do the same thing by hand but a router and template makes it easy. It helps to practice a few times on comparable scrap stock first. In order to get the cutting and under bevel just right. Good luck.

[Jeff Kelety]

Thanks all -

I don't think the integrity of the plank is at issue. It's just very unclean around the chainplate fastener, enough so that the splintering pieces aren't holding a paint seal and up comes the paint. I'm inclined to approach it as RGM has suggested, just giving the face of the wood some solid wood. I don't think I would have to dig in more than 1/4" to get to clean wood. The 1/2" I referred to in my initial description was the width of the divot, not the depth.

So RGM, how do you hold the template up to the plank, screw it on?

Thanks again for the input. As I've already been out of the water for six weeks, I think she'll go in this Friday and I'll leave this till next year, but I'll save these notes.

Cheers,
jgk

[RGM]

The template can be held in place with screws, or nails. Sometimes, depending on the area to be repaired you can come up with some creative methods that don't involve poking holes in your boat. With the nails or screws you do end up having to deal with the fastener holes. In my haste last night when I wrote my initial response I neglected to mention that when you go to cut out your graving piece, whether by bandsaw, jig saw or by hand saw, leave the line. That is, leave a little material along the cut line, just a whisker, say a 1/32" or so. Take the piece down to the cut line that was left by the router by hand as you are fitting the piece. I always try to lay-out my work, no matter what it is, in such a way as to "leave the line", you sort of adjust for the width of your pencil line or pen line. I prefer to use a pen instead of pencils for marking. If you take the line, take it by hand unless you're very practiced with your machinery, during your final fit-up. By "leaving the line" you'll always know where you've been with your power tools or hand tools. Once you take the line it's hard to tell where you've been with your tools and your results will tend to be less satisfactory. So, once you have the graving piece dry fit, pre-drill for your fasteners, remove the piece gently (don't disrupt end grain if you can help it), apply the glue, re-install the piece, keeping setting it back as the excess glue escapes thru your pre-drilled fastener holes. Once the piece is firmly landed throw the fasteners into it. Some people like to leave a small gap around their piece or notch the back of it (serrated look) in order to give the glue a place to go. You may find that a 1 degree to 2 degree bevel is better than just shooting a 2 degree bevel around your piece. You just have to play with it a little bit and see what works best for you. This may seem like splitting hairs, in a way it is. Sometimes it's just as easy to do a job right as it is to do it wrong, it just takes a little info and practice. It is one of the tricks of the trade that works well and can be applicable to many other situations where you want to do inlay work. Doesn't make any difference if it's a table top (decorative) or a teak deck or hull plank (repairs). Except with a table top and sometimes the deck you use clamps to hold the pattern instead of screws. It's worth learning this one. You'll get nice results with a little practice and your boat won't look cobbled together. Sorry this is a little long winded. I hope it helpful. Good luck.

[ 06-19-2002, 11:08 AM: Message edited by: RGM ]

[Jeff Kelety]

One last (???) question here, RGM. What kind of "glue" to use? Epoxy or is there other "boaty" glue that is used in this kind of situation?

Thanks again to all.

jgk

[RGM]

I suppose epoxy would be a good choice here because it's above the waterline, watertight integrity really isn't an issue. It's not really a structural joint, like a scarf, even though it has a chain plate fastener thru it. Epoxy has gap filling capability if so required. Epoxy doesn't require clamping, so the whole issue of mechanical fastening the piece in place is less critical. Gorilla glue would probably work out ok also, but I think the mechanical fasteners would become a little more important. Resorcinol would be good but very dependent on fasteners for clamping pressure, and decent temperature. A nice, tight perimeter joint would be a little more important. Some resorcinols do have limited gap filling capability. Good luck.