Exterior Wood Joinery

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alec

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Sorry it’s me again !

The bloke who’s renewing his toe rail in Iroko.

A few more questions if I may: -

1. The plugs that I made to fit the screw holes fit nice and tight. In fact, I have to hammer them in. Do I still need to glue them ?

2. What glue should I use for the scarf joints ? I have practiced using epoxy at home but I expect it would not set properly in winter.

3. I seem to remember something about using sawdust to fine fill joints etc. Any tips would be appreciated.

4. The transom/stern is a very acute angle to bend wood. Looking around, it looks like most have just carved piece/pieces from a wide piece of timber. Is this the best way to go ?


Many Thanks in Advance.


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I would try Balcotan Glue and its great for mixing with sawdust and filling as it foams up a bit, excess runs of glue is easy to remove.

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I think you might find sawdust a bit coarse, I have used sanding dust from the bag on my belt sander in epoxy, but beware , it sets a lot darker.
I dont know just how cold it is where you are but epoxy goes off as a chemical change rather than just drying out. Check the manufacturers instructions.

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Yes glue in the plugs, they will work out otherwise. Any waterproof glue should suffice for that. I think either Balcotan or Epoxy is suitable but you will have to watch the temperature with Epoxy. Not wishing to be supercilious but you really should not need filling on the scarf joints - get them dead flat and at the right angle and that should be fine.

On 4, not sure what the question is. Are you fitting three new rails, one port, one starboard and one across the stern. If the question is about the transom rail, does the old meet the sides. My stern capping rail was pretty difficult to fit because of the curve. The only way to do it was to leave it quite oversize so that the overhangs could be used to get it into shape. Then I had to cut either end at a bevel to meet each side. I then fitted each side and had some fine judgement to make to cut the length and bevel of that right. It was less of a struggle to get the sides into shape at the stern last because the sheer was upwards.

Does this help?

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1) Yes, you must glue them.

2) Waterproof glue. Extramite (New name for Cascamite) should be fine as long as you can cramp the joint while it goes off.

3) As others have said. a) You shouldn't need to fill scarph joints. b) If you have to , use the finest dust you can (sanding dust).

4) Without seeing what you are talking about I can only guess. If the radius is too small to allow you to bend a piece of timber around it, then it is usual to carve a corner piece from a wider piece of timber, with the grain being tangential to the curve, i.e. for a 90 degree angle the grain would be at 45 degrees. If sufficient choice of timber is available, a piece with grain that curves in the right direction should be chosen.

Hope this helps,

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
I dont know about Extramite, but Cascamite was NOT waterproof. It is water resistant, but prolonged exposure to water will eventually disolve the glue. It was not suitable for exterior work on a boat. The new foamy one (Yes it is available from screwfix!) is much stronger and more suitable.

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Don't glue the plugs in - dip them in varnish first. That way, the poor sould who has to remove them in in x years time won't have to spend hours getting them out with a drill or chisel.

Balcotan would be excellent for the scarph.

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I see you have had some differing replies and as I beleive some of them will not give you the best job, I thought I would give my views too. You will have to work out which advice is the best:

1) when using Iroko do not glue the plugs in. Coat them in varnish, that is all you need to do. People's advice about gluing plugs in is usually from experience with woods that are less stable in varying humidity levels than, for example, Iroko, Teak or Oak. I have never had a good fitting plug using the above woods fall out without glue. If you ever need to remove the part again you will curse the day you glued them in.

2) Balcotan glue is very good and is less sensitive to low temperature compared with Epoxy, BUT, contrary to what many users believe, the fact that it foams to fill gaps does not make it a gap filling glue like a filled Epoxy. Yes, the foam fills the gap, but the foamed Balcotan is very weak and the joint will soon fail if all you are relying on is the foamed glue to hold the parts together.

3) Cascamite (or whatever it is called now) glue is not completely waterproof. It is certainly not suitable for continued imersion. Yes, it might be OK for a rub rail that only gets a splashing from time to time, but I do not believe it is worth the risk. If the splices come unglued in a years tme you will have to do the whole job again (but if you put the plugs in without glue you won't be quite so depressed:) )

Hope these views help.


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Re: Cascamite/Extramite

I was not advocating the use of Extramite for constantly immersed joints. I know you raggies like to get your toerails dangerously close to sea level, but if they are constantly immersed you are in big trouble:-)

Extramite is a glue intended for exterior joinery. I have used it, and its predecessor, Cascamite, for years, and have never had any problems with it coming undone because of contact with water. In fact it used to say on the tins that it was suitable for small boat building. I notice that Extramite no longer makes that claim.

I've never had the opportunity to try Balcotan, it's not sold here in Alderney,so I can't comment on it.

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
Re: Cascamite/Extramite

Bolcotan is a moisture curing polyurethan glue. It is very strong when (like any other glue) parts are fitting well. The fact that it foams will fill bigger gaps, but not very strongly.

I have used lots of Iroko in my boat and you cannot get much better, but it has to my mind two problems.

It contains lots of oil or resin and burns like hell, for the oiliness, you must rough the joints for best results. Otherwise Iroko is super.

regards from africa where iroko grows.


ongolo

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Re: Cascamite/Extramite

Be warned Blue - B - use all your Extramite first before trying Balcotan (mail order) - you may never want to go back to it!!

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Can't argue with any of the above responses but just to clarify:

If you use varnish instead of glue for the plugs make sure you use plenty of varnish and insert the plug while the varnish is wet. The point of the varnish/glue is to stop water getting in behind the plug. Personally, I would glue them. Removal isn't as hard as folk make out if you use a flat bit with a modified tip.

Balcotan (or similar PU glue) is fine for the scarf so long as you make the mating surfaces completely flat and are confident that you can clamp it up tight (easy to do on the bench: harder when assembling the scarf in position).

If you are worried about gaps use epoxy instead of Balcotan. If the weather is cold make a little insulated box/tent/cover for the joint and fit a 40W bulb inside to keep it warm until cured.

For either Balcotan or epoxy it is important to key the mating surfaces with sandpaper (e.g. 100 grit). Take care not to 'round' the nice sharp edges of your joint when rubbing with the sandpaper.


<hr width=100% size=1><A target="_blank" HREF=http://www.qei.co.uk/spark.html>http://www.qei.co.uk/spark.html</A>
 
Even better. Make the tent/cover a bit bigger and keep the worker warm and dry too.

Given the glowing reports on Balcotan, I'm going to have to try it. Who sells it by mail order? Do they have a website?

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
Here yo go BB - try these below - the gent is very helpful.

Melco Bonding Supplies
Ian Wilson
Fiddlers Green
Shop Lane
Congleton
Cheshire
CW12 3AW
TEL & FAX: 0 (44) 1260 276997


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Alec, you already have plenty of advice, but having just gone through an almost identical task I can't resist the temptation...

Answers:
1. YES, definitely. Varnish alone will surely suffer from water penetration and look awful plus leed to the paint or varnish peeling off around some of the dowels.
2. Though pricy, B&Q's fast setting epoxy goes off quick, even when its very cold. Or just add extra hardner to your usual brand. If the temperature is over 2 degrees C you should get away with it, but beware of problems with damp weather. You need dry weather. Cascamite (Extramite) is easy to use and copes with a wide variety of weathers. I recommend it for this job.
3. We used to call the mix with sawdust 'glue and poo'. You need a runny mix of Cascamite and plenty of very fine matching sawdust from under a saw bench. Awful stuff. Fills a gap but has next to no strength. Try to get a perfect fit so that no gap filler is necessary. If you still need gap filling glue, then an easy solution might be Araldite, which comes up really thick, especially in cold weather. But the gap will show creamy white. Araldite is pricey, so only for small jobs. Alternatively, West Systems sell the various fillers and give advice on using them. Also pricey.
4. Yep. On my boat, the starboard quarter timber at the join of toe rail and transom has been replaced by first laminating up a thick piece of timber from off-cuts (teak in this case), then cutting the resulting big timber down to size. Iroko is not very suitable for steaming and bending. The nearest timber in look that will bend well is Ipol, I believe.

Hope the above is helpful. Isn't Iroko pleasing to work with, eh? I read recently that the best way to preserve iroko is to soak it with many coats of linseed oil first before applying a linseed oil based varnish, like Tonkenois. The wood goes a rich dark colour. Makes sense. I've had good results with Tonkenois on teak.

Good luck.

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Re: Balcotan

<A target="_blank" HREF=http://www.screwfix.com>these chaps sell it</A>

<hr width=100% size=1>I employed you people to get a little railroad laid, not to dance around like Kansas City faggots!
 
<Glue and poo>

Reminds me of the old Bodger's Motto.

"If at first it will not fit. Fill it up with glue and sh*t."

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
Re: Balcotan

Looked at that Screwfix link Penfold. Couldn't find Balcotan on there though. Maybe they call it something else?

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
Re: Balcotan

Looked at that Screwfix link Penfold. Couldn't find Balcotan on there though. Maybe they call it something else?

Bill.

<hr width=100% size=1>One of these days I'll have a boat that WORKS
 
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