Advice regarding repairing a crack on a wooden hull

[Paul Hunter 2Participant @paulhunter2]

Hi,

I have been into radio control models for many years, mainly circuit cars.

However when I was a child some 40 odd years ago my father built me a large wooden cruiser which was remote controlled with a large lenght of cable from shore. It has been stored in the loft at my mothers house for may years.

I have started to renovate the boat and convert it to R/C with a view to joining a local club and getting it back on the water this summer. However there is a crack in the hull running along the side of the keal.

I had intended to run a bead of Devcon epoxy along it to repair it. However it appears that the epoxy is ony water resistant?

Although the repair will be painted over, I do not want to use the epoxy if it will not do the job. What is the best product to use to repair this crack?

On a seperate note, I have recently aquired a boxed unstarted 1970's Precedent Hanseat Kit which I am looking forward to getting built for summer 22. However the instructions are somewhat vague so I may be needing further advice once that project is started!

Thank you for any advice you can provide

Paul

[Paul Hunter 2Participant @paulhunter2]

[Richard SimpsonParticipant @richardsimpson88330]

Just a thought Paul, firstly if you put putty over the crack the crack is still there and there is a danger than the flexing of the adjacent hull will crack the putty in the future. I would rub it back to bare wood inside and out, use fibreglass cloth and fibreglass resin and put cloth over the crack on the inside and paint the area on the outside with resin and possibly even some fine cloth to help.

If you do this then rub it smooth, degrease it, rough it up and give it a good undercoat and a couple of top coats I'm sure it will hold the crack together. It might also be worth considering drilling a hole at either end of the crack to prevent it propagating in the future.

[Ray Wood 3Participant @raywood3]

Hi Paul,

Welcome to the forum, all Richards advice is sound, really depends on the size of the crack your dealing with, If you could post a photo, you would have to create an album to put a photo in.

We will be very keen to follow your Hanseat build, is it a big cruiser ?

Regards Ray

[Paul Hunter 2Participant @paulhunter2]

Hi Guys,

Thank you for the advice.

As sugested I have just created an album with a couple of pics of the crack I am trying to repair, The boat is about 4 feet long and the crack runs about 3/4 of the boat length

The Hanseat Kit is a large cruiser, it is 51 inches long, I have also added an album of it and will add to that album once the bulid gets under way.

Thanks again for the advice

 

Paul

 

Edited By Paul Hunter 2 on 06/01/2021 19:57:28

[Richard SimpsonParticipant @richardsimpson88330]

I think you definitely need to rub that back to bare wood to see exactly what is going on.

[Paul Hunter 2Participant @paulhunter2]

Hi Richard,

I will take your advice, rub it back to wood and then use fiberglass cloth and resin to repair inside and out.

Thanks again

Paul

[Fred wooleyParticipant @fredwooley76212]

if the Crack is not inside the hull I am pretty sure it is simply cracked paint and thats all….run the back of a sharp chisel along it and then use a scalpel to see how far the crack !!!!!! goes into the wood…as I said i am pretty certian it is simply a build up of paint and thats all….worth a try BEFORE you go mad with sanding

Stav

[Richard SimpsonParticipant @richardsimpson88330]

I think that even if this is only a crack in the paint on the surface there is a possibility that water may well have done damage now to the underlying wood. Sticking a scalpel into the crack will not tell you anything about the condition of the wood and whether it is still sound. The only way to be sure is to rub the crack back to bare wood so you know you can have a good look at the condition.

Then, as long as the wood, damaged or not, is completely dried and soaked in resin it will be recoverable. No one is suggesting going mad with sanding but having a look at the condition of the wood is worth the effort. If the crack is only in the paint you haven't lost anything as the first job of repainting should be rubbing it down anyway.

Edited By Richard Simpson on 06/01/2021 22:42:31

[ashley needhamParticipant @ashleyneedham69188]

Much as I agree with Fred that it is likely just paint cracking, you do need to be sure and given that you will be repainting this anyway then rubbing down is the way to go.

Paint gets old and either needs sealing or renewing later on. Generally I put as little paint on as possible, as the more layers there is, the greater the chance of cracking in later years.

Ashley

[Colin BishopModerator @colinbishop34627]

Topic tidied up. Let's keep things civil please. Advice is offered on a goodwill basis for consideration and it is up to the enquirer to decide which course to follow.

Colin

[Tim RoweParticipant @timrowe83142]

Hello Paul

None of us have seen your boat close up so all of us are guessing slightly.

To answer your first query, properly mixed epoxy is extremely water resistant and resistant to many chemicals. One of its very few downsides is that it is not resistance to UV light which makes it go opaque and chalky.

If not too late here's my take. I like a minimalist approach as sympathetic as possible to the original construction. It is wood so it will naturally move about a bit with changes in humidity. It's been in your mum's loft for a while and hopefully that was dry. The crack looks to me like a shrinkage crack along the joint.

I am not a fan of glass sheathing a boat unless in exceptional cases and I don't think your boat is that bad (at least from the photo). In your case it would be difficult to glass over the nail heads and the rails and not knowing what the inside is like, likely to be equally hard there. Once you have glassed the hull the would still be a lot of work rubbing down and finishing to stop the repair looking ugly.

I would scrape away the loose cracked paint and seal the gap with a paintable acrylic sealant (not silicone). Any hardware shop will have this. By carefully working the sealant into the gap and then smoothing off, the repair should be almost invisible retaining the full character of build. Furthermore, the repair will be flexible and if the boat wants to move a bit, it can. The danger of making a "hard" repair in one location is that it moves the stress and the problems to another location.

In my opinion it would be strange for there to be any rot. Model boats don't spend much time in the water and if your boats are used in sea water rot is even less likely. If the there was rot due to long term storage you would expect to find it in other areas. In any case there are wood hardening products easily available you could use to treat any small areas soft timber before sealing.

Take small steps before big leaps to avoid unnecessary work or even spoiling the model.

I am a shipwright and yacht surveyor and have recently managed a restoration of a 40' wooden yacht built in Baltimore USA in 1948. There were a number of areas where the acrylic worked wonders.

Just another point of view.

Tim R

[Rich Griff 2Participant @richgriff2]

Hi Paul.

That does not look good, the crack in your pictures in your album. Screw below it and two "bursts", whyich are not too clear in your pictures.

 

What's it like on the inside of the hull, and a picture of the whole boat would be good.

 

If it where mine I would scrape/sand back for a better assessment. Maybe some wood has decayed.

Research an other thread on here about a crack in a destroyer, well worth look around this forum anyway, to see other stuff and how others do it.

 

The destroyer thread about a crack mentions a thin sealer that I have never heard of before, so look and learn.

 

Take your time, assess, more arvise if needed, decide then act, but most of all enjoy.

The loft is not the best place to store models, extreme heat in summer and the opposite in winter.

 

Remember old paint equals LEAD.

If it's a boat, use brass or s/steel or similar.

 

Edited By Rich Griff 1 on 09/01/2021 13:26:36

Edited By Rich Griff 1 on 09/01/2021 13:29:47

[Paul Hunter 2Participant @paulhunter2]

Thank you all for your ideas and suggestions so far. I rubbed back some of the paint today to reveal the crack. The wood appears to be i reasonable condition, other than the crack of course.

As suggested in a couple of responses, this may have been casued by the wood drying while the boat was stored in my mothers loft for a number of years in possible extreme heat in the summer months.

The insde of the hull is of a slightly different design to the outside so this joint is not visable inside the boat.

This boat was built from scratch by my father and the superstructure does not detach from the hull making access difficult. It is also likely to make it challenging to convert to R/C.

First things first though I need to address this crack.

I realise it is difficult to assess from a picture but from what can be seen willl it be most approprate to fill with epoxy (or similar) or is fiberglass the best option.

Thank you

[Ray Wood 3Participant @raywood3]

Hi Paul,

I kept my power dry on this one, but is only a shrinkage crack as the boat has dried out, and if you see the extra line of pins running parallel to the keel the bottom skin is fixed to a doubler so no need for drastic action, don't even think of fibre glass ! it's a ply boat and would make a bloomin mess ! A good fillet of epoxy fill the crack and still be flexible enough and waterproof, you don't need to paint the epoxy either, the boat I would leave in it's original colours as a patina of a bygone era, it would also be a shame to cover the history ? (my view only)

I only use the cheap epoxy from Poundland ! save the Devcon for the Hanseat

I have in my view wasted hundreds of pounds on "model shop adhesives" I don't anymore.

Regards Ray

Edited By Ray Wood 2 on 09/01/2021 20:03:27

[Richard SimpsonParticipant @richardsimpson88330]

Paul, Now that you can see what you are up against I completely agree with Ray, this looks like a shrinkage crack between the ply and the keel and sympathetic filling will probably do the job well enough.

As Tim suggests perhaps painting something very fluid first and letting it soak right into the crack before going over it with filler might be well worth considering.

Good luck!

[Charles OatesParticipant @charlesoates31738]

Hi Paul, it's great that you are restoring the Hanseat, it's a great looking model, one I always admired back in the day.

As has been said, shrinkage like this isn't unusual in an old boat, it's a repair I've done more than once myself, and not difficult to get right. In the old days I would have cleaned out the gap, cut strip wood to size and glued it in, then sanded and re finished the hull. Luckily we have much better materials today, acrylic filler is one of them. I suggest you follow Tims advice, the repair will be sound and it will last. Like Ray, I wouldn't go near resin/ fibreglass for this job, it's not what the stuff is best at.

Another thought for you to consider, as you have the hull stripped down,, it was normal to use a centre punch on the nails so they sat bellow the surface, then fill the recess before sanding and painting. The trick is not to send then right through the wood. It's no big deal, and you might prefer to have it as your dad made it.

Keep us posted on your progress, and good luck.

Charles.

[Paul Hunter 2Participant @paulhunter2]

Thank you all for your advise regarding this, I think I now have a plan to move forward with this project now.

I intend to keep it as close to original as possible and how my father built it. However I think I need to accept that the boat was bulit 40-45 years ago and once back on the water, will only be taken out occasionally.

I will post some more pics in the album as this progresses and once back on the water.

Thank you all once again

Paul

Edited By Paul Hunter 2 on 10/01/2021 17:50:25

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