What kind of putty works filling in hull depressions?

[Jim in KC]

I'm a newbie working on a 1850 Swift Pilot Boat.  I'm about ready to do the second planking.  The first is not terrible but there are some places that need evening out or smoothing the transition between the hull and the bulwarks.  I've looked at all the finished models of this kit and several have used putty for this purpose.  I've read ahead in this section about a year but didn't see anything specifically on this topic.  Any recommendations?

[barkeater]

Wood putty from your local hardware store would be fine. Just be sure that your gaps are not to big as your want to glue your second planking to wood and not putty which does not have the holding strength. Also sand well so you have a smooth surface without bumps or ridges.

Richard

[Jim in KC]

Thanks barkeater.  I was thinking of some kind of modeling putty that would dry hard, could be sanded and also something that you could glue a plank to and would hold.  Any ideas anyone?

[Jaager]

From an outsider and theoretical perspective:

What is the need to fill the gaps between planking with anything for the first layer of a two layer POB hull?  The entirety is covered by the second layer.

If the problem is hollows between the molds - PVA glue a scab layer of wood veneer at the hollow.

Pine or Basswood should be soft enough not to resist paring more than the actual first layer.

For really shallow dips, a curl of Pine made using a plane should be a proper thickness.

Edited March 27, 2023 by Jaager

[Jim in KC]

Thanks for the input.  I have been thinking about using scrap wood to fill in where needed.  The reason I thought of putty is that several finished 1850 Swift boats have mentioned using putty.  See particularly the Swift by Stripehunter - I really like the way his hull looks after the second planking.

 

 

[CLovehitch]

You can use spackle or Durams Water Putty, great stuff you can control the consistancy, dries very hard and sands well!

[Robere210]

Ditto Durhams Rock Hard Water Putty.  It is tough, and expands a little bit as it dries.  I've used it for many years, tho never on a model boat build.

[mtaylor]

I'd be a bit careful using something like "Rock Hard".  If the filler putty is much harder than the wood, the wood will get sanded down faster than the putty and create more problems.   Been there, done than on a piece of furniture.

[georgeband]

If it's not too late to add to this thread...

When I have a plank that sits too low, usually where it takes a short cut between two bulkheads, I cut a short length of the same plank material and glue it onto the one that dips. The width of the plank is often a perfect fit though sometimes it needs a taper. 

The first photo below shows where I went wrong in a few places at the bow of Whiting. I glued on the strips, sanded them, and then sanded the whole hull. Second picture is after sanding and the ends of the patches can be seen. 

 

George

 

 

[JeffT]

I've been using Bondo all purpose putty. Works well.

[Bob Cleek]

From my boatyard days, I've always been a big fan of Interlux surfacing putty. It is thinned with acetone and you can vary the consistency of the putty from thick cream you can brush on like gesso to stiff "cake icing" consistency. It's applied with a putty knife. Store it capped tightly with a tablespoon of acetone added and the can left upside down overnight and in the morning, the putty will be ready for use without any dried clumps in it. the bad news is that the acetone solvent evaporates very quickly and if the lid is left off the can, there can be annoying "skinning" of the exposed putty. (You have to develop the ability to hold the can and lid in one hand and the putty knife in the other, closing the lid immediately after accessing the putty in the can.) The good news is that the acetone solvent evaporates very quickly, which makes it easy to use because there's a very short drying time wait and successive layers can be built up if need be. It sands "like butter" and is compatible with all paints. It's the perfect thing for filling small dings, scratches, and other surface imperfections. Rather than sanding forever to remove a small imperfection, which only tends to create an unfair surface overall, it is far better to add a swipe of surfacing putty and then just sand that fair without having to remove a lot of material surrounding the imperfection. It's also a lot faster than sanding out similar imperfections without putty.  See: Surfacing Putty Boat Filler | Interlux Sold online and in marine chandleries.

 

Edited May 26, 2023 by Bob Cleek

[robert952]

This thread is a good example of why I like the forum.  State a problem, ask for help, get multiple solutions to review. Pick what works best for your project.  Though not a current problem I have, I'll file the info under - 'just in case.'