Hull thickness

[CapnK]

Anyone know how thick your Ariel hull is above and below the waterline?

I'd guess that it would be comparable to other boats of the same age - ie: 1/2"-3/4" above WL, 1" thick below?

Thanks in advance -

Kurt

[ebb]

It probably will be suggested that one should type in the above phrase into the SEARCH option (Finding the SEARCH option is for me becoming another SEARCH option because the ikons are so tiny.) Why are they so TINY???

But I just did that (have to remember SEARCH is second one in from the right...)
.....and the stuff one has to wade through is WAY above wading depth. BLUB B L U U L B.....

So AYE know full and by what 338's hull thickness is, but not exactly at the waterline. I'ld like to hear what yawl got. Be real nice to hear from the early boats, and all the way thru to the end of the 'run.':cool:

[CapnK]

Aye aye - no net newbie here, tried the same as you but after many pages of looking did not see any figures, so thought I would ask the question phrased in just that manner, and if anyone cared to impart an actual figure or two, maybe it would save someone else some o' that same fruitless wading in the future, as well as answering it for me now. ;)

So - anyone have a figure they'd care to share?

[marymandara]

Min to max, deck join area to thickest area at bilge turn...

My old Commander, checked with a hacklinger guage, ran out to appx. 1/4" to 7/8", which curiously is about what my Triton is. The keel is thinner, maybe 3/8 to 1/4 judging by the places I ended up drilling. There is a fair bit of variance in the hulls too, these boats were rather, uh, hastily built and there are allowances for that. Supposedly the production tolerance on hull thickness is +/- 1-16", although I know one fellow has a Triton hull that is more like +1/8" strong...as in, a healthy 1/8". Another interesting detail is that the boats were engineered to be able to sit on the edge of the keel and lay on any one square inch of hull without damage. Whether or not that would hold true for a 40-year-old and somewhat embrittled boat, I can't even want to guess...but it does inspire confidence.

Best,
Dave

[Scott Galloway]

I am interested in the sentence in the preceding post that said,

"Whether or not that would hold true for a 40-year-old and somewhat embrittled boat, I can't even want to guess...but it does inspire confidence."

Does anyone have information on the aging process of fiberglass laminates in boat hulls? We all know what happens to the wood sandwiches that we call decks, but what about the aging of the solid glass hulls we trust to carry us over the briny blue? Does fiberglass actually become "embrittled"? Anyone know of books or articles on the subject?

From surfboard repair work, I know what happens to surfboards exposed to excessive UV light. To some degree, the gelcoat covering our hulls offers UV protection, but has anyone actually done an analysis of the aging process in boat hulls.

I recently witnessed the demolition of a 1960s vintage Columbia Challenger, and the glass looked great. Not only did the hull and deck section superficially look as good as new, but also the glass was fully wetted out and the boat was put together well. Like the Ariel, the hull deck seam on the Columbia Challenger is a cold joint, which depends solely on the limited chemical bond of that cold joint (no fasteners). And by the way, if you haven't taken your Ariel rub rails off and re-bedded your hull deck seam, do not delude yourself into believing that those screws in the rub rail have anything to do with mechanically holding the hull deck joint together.

It would seem to be a fairly simple thing for a knowledgeable and skilled researcher to do to take some hull pieces of older boats like that poor unfortunate Challenger, which find their way onto the beach and thereafter to the scrap pile, and subject those pieces to destructive testing. Marine authors like Linn and Larry Pardey extol the virtues of 1960s boats like the Triton, based on the strength of the hand laid up hulls, but has age undone the advantage? The other thing I would find interesting is a comparison of the aging process of pre-1972 high Formaldehyde resin that we find in our Ariels and Commanders and Tritons in comparison to the resins used after 1972

[ebb]

Our poly-resins were indeed the best resins EVER used for boat building. I tried to find out about the aging polyester/fiberglass anamoly and talked about it here somewhere. The Navy did some tests on old launches and barges once, I think it was in the 80's, and they found nothing happening. But I remember thinking that the testing may not have been smart enough. IMCO.

A sharp chisel forced sideways into the laminate has a disconcerting way of peeling layers of mat and roving. The stuff is harder than hell if you try to bang strate thru it. But sliceing in...TOO easy. Whether that is age and brittleness, who knows. As you point out, no engineered tests have ever been done on the strength or brittleness of the plastic of these frp boats of ours from the 60's.

Dave intimates that that the A/C hull is thicker in the middle than at the sheer or in the keel area. 338 is approximately 1/8" and 3/8". The 'cold' joint is approximately 1/4". Haven't gone into the mid section, but would be really surprised if the hull was any thicker in the turn of the bilge. The stem was about 5/16s (horrorfied, it has since been considerably beefed up!)
The transom, which has been carved into on 338 is about 5/16s in the flat and thicker in the corners.

Wouldn't you guess that even the casual paint jobs, washing, cleaning, waxing even, have helped to preserve the plastic? The gelcoat could be the major factor in the perservation of the A/Cs. The deck on 338 has no deterioration under the gelcoat I can see. The laminate is just as green and fresh as the day it left the factory.

:D

[willie]

Don't know yet on 350, but am about to with the thru hulls for cockpit drains.

So getting off topic a little, does anyone (ahem) have a special drill bit/tool for putting the taper in for the flush Forespar marelon 1 1/2" thru-hulls? Or where can one purchase such an animal? Kinda not really something i will use everyday, so thought i'd ask one up.

Also, anyone know why the mushroom head 1 1/2" hose barb t-hulls fit snug in the hose, and the flush head ones don't? Man, this boat stuff....

I think i'm making progress on A.M., will post a few pics in the gallery for your viewing pleasure. Comments, h.o.'s gladly accepted.

Please respond to the tapered hole dilema. Thanxxxooo

[ebb]

THE BEST tool you'll ever buy is the

Nicholson #49 hand file (not any other Nicholson, you'll never find this babe in the hardware store.)

Fiberglass cringes befor it. You can find the best price, too much but worth every dollar, in the Jamestown Distributors catalog. They even had an unheardof special on them not so long ago. I didn't get enough.
It does last a good long time rasping away at frp...

It'll put the taper in the hole in less than a minute.
Jist stan back and watch it do its stuff!!!

[marymandara]

Die Grinder. Carbide Burr. Vrooommm!

Cut the dish a bit sloppy is OK, a bit deep is OK...bed it in to the desired depth with 5200 and fair over the top of it...perfect job!:D

Alternatively, 4-1/2 or 5" cutoff disc in a hispeed-type body sander...lay the spinning edge against the opening and then sort of rotate the tool. Just...don't hang it up, and don't jump the tool. Watch your eyes...not OSHA-approved, but works just fine.

Dave

[willie]

That's it???!! Well, sheeeeh. I could have come up with that! I thought maybe there was some fancy smanchie tool you experts used. Ok. We'll do it the farmer way. Worked ok so far....

Thanks for the confirmation though!:D

[ebb]

Davee,
How you get a 4" disk in a 1 1/2" hole? A carbide burr will do a fine 4 or 5 degree taper. I'll taper the above hole in 30 seconds with the half-round 49 while you're still fidlding with the chuck key!:p

[marymandara]

You just get the edge in the hole... Like, 90 degrees to it! Like I said, not for the faint of heart!!!!;)

[willie]

I knew what ya meant! I think with my shoulder i'll go with a file. I got lots of time. And the backing blocks--3/4 ply glassed in ok?
I'd think blocks would be a good thing with flush mounts.

[marymandara]

Oh Jeez...3/4" ply is more than plenty! Make sure and utilize those ears for the thru-bolts on the seacocks, BTW...otherwise the only thing supporting the whole affair as the 500-gallon Igloo Ice Chest slams it...is the thruhull shank! I know, any good fireman/rancher...let alone most of us boat-monkeying meatheads...can see that as a must, but you would be surprised how many seacocks I've seen installed w/o thrubolts (including original Pearson ones!)

Now here is one that will get me drummed right out of the cool-guy boat-refurb club...but I just gotta toss it in...
Bedding those backing plates. I spent hours and hours one day fitting one to a hull contour, many sheets of 80-grit ductaped in place one after another, stroke, stroke, stroke. Dad informed me I'd done a great job, but he'd go ahead and do the other one...which was done in about 5 minutes! Stuck the plate in place, held it up where he wanted with some window-setting wedges and tape, paste-waxed the death out of the thruhull's threaded shank and had me run down and screw it in so he could get everything wedged tight where he wanted and dead square...then packed the gap under the backing plate chock-a-block full of good old Bondo. OK, let's 'glass 'er up! Sheesh!

I still do not see anything wrong with doing it this way, quite honestly, as long as the thing is well-bedded so as not to get the bondo wet and the thing is well-glassed over. It's just taking up space, after all. If we feel like it needs to be real cool, we can even use epoxy over it all, or e-glass the thing in...but since it is really only filling in space, and since hopefully we're using something full of mill fiber like Duraglas 'Long-Strand' or Evercoat 'Kitty Hair'...might as well pack it full of something that was only 20 bucks a gallon and set up in minutes! The glass you put over...is what really carries the load here anyway.

My .02 for today
Dave

Dave

[ebb]

Dave,
Yer absolutely correct.
I was not thimking.... the disk grinder will easily cut the dish taper. Somehow I was thinkin long taper like cork in bottle. (I use rhe smallest Makita 4" angle grinder I could find. For grinding I use those hard laid up rigid flap disks. Used many kinds and brands, the best is probably the Makita $$disk, it's stacked taller so the flaps are at a more acute angle. Made for paint removal and grinding the inset for flush thru hulls. Spreads dust and glass everywhere.)


I think it important to back up a flush thruhull very well. (I'm thinking 338 - at most 3/8" in the hull.) More of the hull has been wasted to take the fitting, my way would be to thicken the hull around the hole with mishmash. If stiff enough, you can plaster it out into a flat mound and push a square or triangle of ply with double sided carpet tape on it. Leave the peeltape on it, epoixy won't stick. When set pop the thing off and you have a glass smooth surface to mount the three point seacock to, Drill the hole from the inside exactly where you want it. Champher the hole and set in the thruhull. If the pad was thick enough (would you accept 1"?) you could probably lag the seacock to the pad. Because the thruhull would be much stronger than normal installs. Ver' strong unit. And you won't have 4 holes all in one spot.

Anybody in the shop, say what??

Depending how 'mechanically correct,' how clean, this method would turn out, I would consider using bedding compound rather than rubber for caulking. Just think how easy it would be to take it apart - when you have to, and you have to.

Anybody in the shop care to comment??


......Or, put the glop down, spread it around, cover it with plastic, press it and push it into very nice smooth shape indeed, flatten the spot where the fitting will go on the visqueen with a piece of scrap, leave it. peel and go. Helouise.

[walberts]

When I drilled the hull (#133) just forward of the ballast and slightly above, the thickness ranged from 2.5" down lowest, to a bit more than 1" a foot higher up. I drilled 9 holes and those are the averages. I was surprised how thick the hull is just forward of the ballast, right above the keel's bottom. 2.5" is no exaggeration. In fact it might be a bit more than that.

[CapnK]

Thanks for all the replies! :D

[Theis]

The answer to the question about a tool is the Dremel Tool. I waited about a year after I started the restoration, and finally broke down and bought one. If you thought duck tape was the cat's whatever, the Dremel Tool cures colds, fatigues, makes dinner, feeds the dog, just about everything you could think of.

Now as to the hull thickness: I put a copper plate (to discharge lightning) into the bottom of the boat at the bottom the hanging locker in the cabin. That required I drill a big hole in the bottom. My guess is that the hull at that point is about 1/4"-3/8" thick. I didn't measure it but it was not as thick as I would have imagined. I also did work on the keel (drain plug) and found a similar thikcness.

My understanding is that the way these boats were laid up is they just continued to lay glass cloth layer upon layer until the weight of the hull reached the design weight. The layup was more subjective and subject to expertise - and therefore variation should be anticipated.

My experience has been that the layup was all glass cloth. I don't recall encountering any filler mat. Since the cloth is what gives the glass the strength, and if filler mat was not used, a thinner hull might be stronger than a thicker hull with matt separating the layers of glass cloth. That goes to the issue of separting the laminations mentioned earlier. Mat is relatively easy to separate, but cloth is more difficult (assuming the material was fully impregnated with resin - the mat doesn't take as much resin, which is why it can be more easily separated).

[Jon]

It ain't all that thick.... Today I went to do a little work on Sirocco. I have a problem with water draining down into the benches after a rain and when it pools it soaks my cushions....fore and aft. We got a great rain last night and sure enough...water had pooled in the little grooves where the wooden seat meets the bulkhead. I took a 1/4" drill and drilled into the bench, following the angle of the hull. Didn't drill far and drilled right through my hull. Water started pouring in and it pooled under the benches....would not run into the bilges. I had to drill a 1/4" hole where the vertical part of the bench seat joins the deck to drain the water which continued to flow into the bilge. Got with some guys and plugged the hole with marine adhesive and now I am going to have to pull my boat, put her on the stands and patch a hole that my "stupid" self accidentally drilled into the ULTRA THIN hull. If I were to guess I'd say the hull where I made my major boo-boo is about 3/8" thick. Maybe less

I have always loved life's lessons and as I am with a few others that I have under my belt, I'm sick about this. But, on the bright side, I'm going to get a chance to pressure blast the crappola off of Sirocco's bottom, cut those seat boards and fix them so they will lift for storage, sand and refinish the cabin sole, fix that hole and hopefully sail this Fall.

My wife told me that the next time I board Sirocco I cannot take any tools with me. She's a very smart girl.