Hull filler.

[bluenose2]

I have started to sand out the first planking on my ships hull to prep for finish planking. I am looking for a recommendation for filler to fair out the dips and cracks. I have tried bondo and wood filler before but it is harder than the planking and I tend to sand out more wood than filler. Also should I prime the hull before final planking or not?

[Srodbro]

I have used drywall joint compound on solid hulls below finish planking without any problem ... can’t imagine why using it on under planking would be any different. 

 

[MrBlueJacket]

You can also try Auto body putty. It is lacquer based and sands easily.

[Jaager]

This is the support layer for the real planking.

I would not do anything to the surface of layer one that interfered with the subsequent bonding of the two layers.

Unless intended to actually float, the hull's inner layer does not need to have 

the gaps between planks in the first layer filled.  The outer layer will cover that anyway.  The

hull fairing and support for a proper planking run repairs are a different factor.

Practice on scrap, but a top quality water based drywall filler with a bit of PVA 

mixed in could do the trick.  Feathering the dips and depressions without damaging

the part of layer one that is correct should be the goal.  A strong bond using a material

that will bond to the PVA holding the outer layer is needed.  It does not need to be tough itself.

Severe dips = consider using veneer - actual wood - as a scab-like repair material.

Edited August 22, 2018 by Jaager

[JerseyCity Frankie]

Dry wall sparkle certainly fills voids but there is an issue with gluing to cured drywall patching stuff: glue sticks to it just fine but the material itself is chalky and a plank glued to it is only attached as firmly as the chalky material is strong. You can pull the plank right back off and it tears out the tiny bit of patching material it was actually glued to. I discovered this on a recent planking job and I wound up having to saturate the drywall patch with thin supper glue to stabilize it enough to hold a plank glued with white glue. I switched to Dap brand Plastic Wood which behaved much better and I was happy enough with.

Edited August 26, 2018 by JerseyCity Frankie

[Maury S]

If you must use filler, try Bondo (auto body filler).  It comes in a squeeze tube which is easier to store and preserve.  

Maury

 

[vaddoc]

Best filler I ve used is Elmers color change wood filler.

The trade ones are very hard and the lightweight fillers from model shops do not sand well. I never liked the PVA/wood dust mix. Elmers is brilliant, applies well, dries quickly and sands very well. You can mix it with water based paint (and probably wood dust), it will still work. When it changes from purple to pale, it is ready for sanding.

[No Idea]

Hi B  - The issue is not your filler its your technique.  I always use a two pack auto type filler which adheres to wood very well but is harder than the actual wood.  Just apply your filler in very thin layers and build up slowly to the level you require with light sanding in between.  Yes it is time consuming but hey its about the building not the how rapidly you can achieve the shape that you want.  Thin layers and patience is the way to go and you will achieve your goal.  Also use a block for your abrasives - it will give you a flatter result.  Good luck mate!

[hornet]

I have found that if you are careful about hull shaping as you apply the first layer of planking, packing out/ trimming planks as you go, there is very little need for filler of any sort. If you are concerned about small gaps you can make a wood dust & PVC paste to fill them. I you are concerned about planks drying out and cracks appearing you can use bandage gauze and PVC - a bit like fibreglassing on the inside of the hull. 

Edited August 31, 2018 by hornet

[Bob Cleek]

Interlux and probably other marine paint manufacturers make "surfacing putty" or "glazing putty" (not for window panes!) used to fair surfaces when finishing topsides and other gloss surfaces. It's much like drywall plaster, but is oil based (thins with acetone) and dries hard rather quickly. It is made to sand easily, but has a very fine grain. It's softer than the wood, so you don't get an uneven surface when sanding. It will go off in the can (keep the top on at all times except when taking some out,) but is easily "rejuvenated" by simply putting a small bit of acetone on top of the thickened putty and storing the can "top down." (The acetone evaporates very quickly.) Overnight, the putty will evenly reabsorb the acetone solvent and return to a thinner consistency. A pint can will last you practically forever. It's an industry standard. I use it on full sized and model boats alike.