Can someone talk me off the ledge?

[Tatheelrod22]

Thanks again. Check the pics out and see if that helps. I look forward to your sketch!

[Cadence]

I think you should counter bore and open the hole in the teak up. Use SS sheet metal screws they will bite into a thin fiberglass surface. Put a small pilot hole in the glass. JMHO

[Suijin]

Ya I would make sure that the screws can pass easily and without restriction through the drilled holes in the teak. You don't want it biting in very much at all. I have a feeling, given your pictures, that when you get that sorted it will go down fine.

This is actually one of those situations where I might go with 5200 for it's added strength. If you ever need to take the teak off in future a razor knife run along between teak and deck would take it off fairly easily. Another advantage of 5200 is longer working time than 4000.

I'm a little concerned about the length of your screws that look a bit short, based on the third to last picture. I'd go with 1/4-1/2" longer...if they are actually biting into anything.

Do NOT epoxy the bungs in! Simply dip them in varnish before you push/knock them into the holes. That will seal them, but also allow you to remove them in future without destroying the surrounding teak. Get a japanese flush cut woodworking saw ($10 at Home Depot or Amazon I expect) for cutting the bungs flush. Super convenient.

[NevisDog]

Maybe a totally different scenario but I was faced with a continuous strip of aluminum sandwiched into the deck below the toerail.

[dgz3]

You won't do it. And neither would I when I was you. But before long you'll wish you had! lol

Put the plastic pieces back on, well bedded and with slightly larger screws, and paint them! Burn the teak so you won't be further temped. Then go sailing!

I looked up the boat. A salty looking little gem, she is!

[Joli]

The screw is lifting the wood instead of biting into the fiberglass. Open up the hole in the teak and maybe consider through bolting.

[Tatheelrod22]

Thanks for the suggestion on not epoxying them in. hadn't thought about how that would affect ever getting them out, and the diameter of the countersink is already a litttle closer to total width than I'm comfortable with so removing by going with a slightly larger countersink isn't an option. I already have one of the saws you mention and I used it on the eyebrow you can see above. You are correct. It's the way to go.

[Cadence]

Originally Posted by Joli

The screw is lifting the wood instead of biting into the fiberglass. Open up the hole in the teak and maybe consider through bolting.

Except he would have to destroy his headliner.

[NevisDog]

Oops, just came across page 2, pictures an'all! Those screws are all wrong - use proper wood screws (the ones that are threaded only half-way up, then smooth), or better still, through-bolt if possible.

[TrentePieds]

Tatheelrod:

You will get the sketch - but I'll have to develop it in between other scheduled work.

For now here is a link to something VERY fundamental about screws:

https://www.glen-l.com/weblettr/webl...b-plate6b.html

Print out this little table and keep it in your tool box.:-)

There are three "parts" to a proper screw hole: The clearance hole, the thread hole and the bung hole. That each is correctly dimensioned is critical to the effectiveness of the fastening.

The part of the screw that is labelled "shank", the bit without threads, must go through a hole that is big enuff to give CLEARANCE so the screw can slip right through. That's why it's called a "clearance hole" :-) The diameter of the clearance hole differs from screw size to screw size. The "size" is the gauge indicated by the numbers., so a #12 screw takes a different clearance hole from a #6. Obviously.

The "thread hole" diameter is ALSO specific to each screw size, and must be less than the "minor diameter of the screw", i.e less than the thin bit of the screw that shows between the threads. The "bung hole" diameter is also critical. The "bung hole" is the part of the hole that has a tapered bottom for the screw head to draw up against. The ANGLE of the taper is also critical, but is standard so that when you use a "countersinking bit" the taper will automatically be correct.

Screws are not appropriate for fastening wood to anything else, i.e where the wood is the "stuck on" bit and the bit it is stuck onto consists of something other than wood! Sometimes, but not always, is it okay to use screws for sticking some other material on to wood.

Where wood gets stuck onto other wood, it is a rule of thumb that the distance the screw must enter the "stuck onto" object must be 1 1/2 times the thickness of the "stuck on" bit so that the total length of the screw to use is 2 1/2 times the thickness of the "stuck on" bit.

If there isn't "goods" enuff in the "stuck onto" bit, to take that length of screw without it coming through on the backside of the "stuck onto" bit, then some other method of fastening should be selected. Very often that means "through bolting" with machine screws, and we'll come back to that :-)!

There are three kinds of "kerfs" in use. Slot, Phillips and Robertson. Each has merit. Where a screw head will be permanently exposed and never bunged up with mastic, glue or other such, I prefer the Robertson kerf (the square hole) because it aligns the driver bit with the centre axis of the screw while it's being driven. However, for "bunged" screws I prefer the slot because if ever you have to pull the screw it is MUCH easier to clean up a slot than it is a square hole, and clean you must for the driver to get a decent grip so that the screw will come out cleanly.

Someone mentioned that you could screw from below the deck into the toe rail. Yes, possibly, but access is likely to be a problem. Even if you could get in to do it, the result would, IMO, be inferior to through-bolting and the labour to do it would be just as much. So stick to the tried and true :-)

I'll be away for the rest of afternoon. More tonight or tomorrow.

Cheers

TP

[Tatheelrod22]

Thanks so much. The chart not only printed, but laminated and will hang in my shop!
What you saw about cleaning up the screw head makes sense, as I've done that more than once with a hacksaw blade.

[Deltasailor]

Originally Posted by jimbunyard

Couldn't be sure from your description if you've drilled a hole through the teak for the screw to pass through so the screw can clamp the toerail to the deck. If you haven't, you should. Teak is generally much harder than domestic woods, so if you have drilled a hole, and it is a relatively tight fit for the diameter of the screw, the strength of the wood can jack the toerail up, bottoming the screw head into the toerail before the bite into the fiberglass pulls the toerail down to the deck.

If this is the case, drill a bigger hole for the screw to pass through, so that it can clamp the rail to the deck.

Another interpretation could be that the fiberglass into which you're screwing is too thin to provide the clamping force necessary to hold the toerail down. If this is the case then you'll have to either go back to the original holes and hope there is a backing block there with enough meat left for the screws to grab and hold (a larger diameter screw might work), or figure out some way of getting backing blocks in place.

A third alternative, not recommended, would be to use a combination of backing blocks where you can fit them and some sort of stainless toggle bolts and adhesive.

As noted previously, 5200 is not the best choice for this application, though if you have to go with the third alternative, it might be necessary,


Teak is not generally considered suitable for steam bending, though it isn't really relevant since the OP says bending isn't his issue...

Firstly Teak may be regarded as a hardwood but in fact is quite soft. If you try to curve a rectangle plank it will twist and lift off the deck. To help it bend cut grooves in the inner side of the plank about 4" apart about 20% of the depth, (try that with a similar piece of pine to see how it bends) that will allow the plank to bend without twisting. Drill a plug depth hole every 6" then a pilot whole slightly bigger than the screw, then apply the plank to the deck bending a drilling as you go. Drilling a smaller pilot hole into the deck and screw down by hand not a power driver. You can then "feel" if the screw has bitten, a power driver will rip the thread out of the deck.
Take the whole thing off, clean away the dust etc., and bed down with a good adhesive/sealant. PVA or similar waterproof glue the holes for the plugs. Wait till it sets then cut the excess plug off and sand gently, TEAK IS SOFT. The bad news is if you want bright work be ready to do it maybe twice a year! I agree it looks good but it don't last long! Oh yes steaming is out as teak is a very oily wood and steam dose not penetrate too well.

[alansmith]

This has been a very informative topic. Thanks to CF affeciandos. Btw, to OP I have a 29 foot Sharpie that I'm fully restoring... also trailerable.. and going through many issues. Keep the faith... it will be your creation and u will be bonded to her like a sweetheart. I'm digging my process even though it has cost me much more than I anticipated

[Jim Cate]

I'm digging my process even though it has cost me much more than I anticipated

Often true with human sweethearts as well... must be a lesson in there somewhere!

Jim

[jimbunyard]

Below are a couple of line drawings that might illustrate for you a couple of ways of clamping the recalcitrant toerail (though I wonder if it might more properly be called a coaming).

The figure on the left, the more expensive option (if you don't already own an appropriate clamp), uses a long bar clamp, and assumes the handrail on the cabin top is fairly well fastened, and that the flange on the lower part of the clamp is pulling against is the hull and not the rub rail...

If the boat is on a trailer, then the inset figure will work just as well and maybe better. Plus it's likely cheaper, if you have some spare line, a couple of 10' 2x4s or 2x6s, and a couple of 1x2s for toggles lying around. Twist the toggles (the short brown lines between the 2 blue lines [rope]) and the athwartship boards will come together pressing the toerail to the deck via the short board between the top of the toerail and the upper athwartship plank. This is generally called a spanish windlass.

While through bolting will be the strongest method, if you can't get access, then you can't through bolt. Since this is a nonstructural, noncritical part, 'screw and glue' is perfectly acceptable. Teak is an oily wood, so the same precautions apply for 5200 as for epoxy; a not-too-smooth gluing surface and a good acetone scrub before gluing.

Wood screws are tapered and are not generally good for fastening into fiberglass because the more you tighten then, the more likely they are to crack the glass.

Finding the proper screw to use in a given application is somewhere between an art and a science. One of the more important criteria (doubly so when screwing relatively soft and gall-prone stainless into fiberglass) is to match the pilot hole to the root thread diameter dimension of the fastener. Another important criteria is thread pitch; while a higher thread per inch is generally considered stronger, the characteristics of the material that the screw is being threaded into have a direct relationship to the holding strength of the fastener.

For this reason, oftentimes the best evaluation of which screw to use is best determined by testing on the actual part; i.e. drilling a pilot hole, either in a later-to-be-hidden area or so that the hole can be used later to fasten the part, and trying to pull it out. In my experience, sometimes a slightly coarser thread seems stronger than a finer one...

The hole through which the fastener passes must be a slip fit, especially so given the height of your toerail. 9/32" or even 5/16" for a quarter inch bolt. You shouldn't use countersunk fasteners in this application; they'll tend to split the toerail. Panhead bolts or screws seating on a perpendicular-to-the-length-of-the-hole-axis flange or lip is what you want for permanent, non-loosening clamping force in this application.

If you can find them, my preference for drive style is torx, followed by square, followed by Philips, though what is available in length, thread
and material trumps the drive type...

Originally Posted by Deltasailor

Firstly Teak may be regarded as a hardwood but in fact is quite soft. If you try to curve a rectangle plank it will twist and lift off the deck. To help it bend cut grooves in the inner side of the plank about 4" apart about 20% of the depth, (try that with a similar piece of pine to see how it bends) that will allow the plank to bend without twisting. Drill a plug depth hole every 6" then a pilot whole slightly bigger than the screw, then apply the plank to the deck bending a drilling as you go. Drilling a smaller pilot hole into the deck and screw down by hand not a power driver. You can then "feel" if the screw has bitten, a power driver will rip the thread out of the deck.
Take the whole thing off, clean away the dust etc., and bed down with a good adhesive/sealant. PVA or similar waterproof glue the holes for the plugs. Wait till it sets then cut the excess plug off and sand gently, TEAK IS SOFT. The bad news is if you want bright work be ready to do it maybe twice a year! I agree it looks good but it don't last long! Oh yes steaming is out as teak is a very oily wood and steam dose not penetrate too well.

Welll...I did actually say

"Teak is generally much harder than domestic woods"

so let's start there.

I didn't define 'domestic', but meant 'generally most available in my specific area', that is the southeastern US (where the OP also is located).

'Softness' or 'hardness' of a particular wood comprises only part of its structural characteristics, but we'll just stick with that metric, for simplicity's sake...

Since wood is obtained from a living, organic source, there is much variation in specific characteristics, not only among individual members of the same species, but even within samples taken from a specific tree!

Be that as it may, here we'll use Janka hardness listings from 'The Wood Database'


Teak..................1070 Janka

Some domestically available (US) woods

White pine...........380
Sitka spruce.........510
Poplar..................540
Douglas fir............620
Yellow pine ...........690
Red cedar..............900
White ash............1320
White oak............1350

I'll leave it for you to imagine which are most available at the local lumber yard or Home Depot...

And just for grins, some truly hard woods (those that I can go out to the shop and lay my hands on at this time...

Honduran mahogany....900 (not really a 'hardwood')
Tigerwood.................2170
Tambootie.................2480
Jatoba.......................2690
Bloodwood.................2900
Cocobolo....................2960
Lignum Vitae..............4390