Cabin hull screws

[CDory23]

Hi all, Last couple times I've been out I've gotten some water onto the floor of the cabin. Melted ice from the ice box leaked out of the fridge and settled to area underneath the stove/sink cabinet. It was only there for a few hours and I'm wondering if i need to worry about the screws that secure the cabinet to the hull floor and other screws in the area that are the holding potable water line secure etc.... They do not look like they were sealed and I don't want to have any hull rot. Do I need to go the whole undercut epoxy route and then put screws back in? Have others ever had water in this area and is it something to be concerned about?

Thanks

 

[journey on]

My comment for what it's worth.

The cabin sole of Journey On filled with salt water when we first used it; a result of a factory screw up. Bilge pump emptied the cabin, factory resealed the anchor locker, etc, etc. There was several hours of wet floor for a couple of cycles.

So, I've pulled a number of the cabinetry hold down screws over the years and there is NO SiGN of water ingress, let alone rot.

I'd take a deep breath and enjoy your boat. Fresh water for a short period of time isn't even going to corrode the screw heads.

Boris

 

[thataway]

I agree that there is no worry from a brief immersion. In the long run it is best to have the screws better sealed. The best is drill out, slightly undercut, and then drill new pilot hole, and put in the old screw. Several issues here. Most of the boats had cadmium pated "L" brackets and screws--which rust easily. You do have the vulnerability of screws.

The easiest thing to do, is to pull the screw, eliminate the "L" bracket and screws from the wood also. drill out the hole enough to fill with epoxy, and then over this area, put a tab of fiberglass cloth and epoxy. You have eliminated the screw in the hull, the hole in the hull, and the "L" bracket.

The down side of this, is it might be slightly more difficult to remove this tab if you want to rebuild the cabinets. I don't see this as an issue. The epoxy/cloth (I used some triaxial cloth I had in stock), takes a very short time--have to sand the area where you are putting the tab, and be sure it is clean. Do every other tab at first, or do some tabs between the "L" brackets, and then pull the screws, and tape over them--so there is no chance of the cabinet moving.

 

[Sunbeam]

I agree that it's best not to have screws going straight into the structural hull core with no protection. Granted, it's not a place that is likely to "soak" in water, but I just find it to be something I don't want to worry about (so I changed mine).

One thought if you are going to tab: As Thataway said, it can make it a pain to remove any cabinetry. Not that you are going to do that every day, but why remove the option ('course you could always cut tabbing, but...). Also, I'd be a bit "meh" on the idea of bonding tabbing to the top (white) surface of the Decragard (you could cut away the top layer, but that's more work again). So if I were going to tab (and I may in some places), I think I would do it how I have seen it done on Albin boats (just for one example). Essentially, you lay up the tab and bond it properly to the hull (sole) as you would normally tab. But, you don't bond it to the "furniture." Instead you lay it up against the furniture, but keep it from bonding (tape, wax, etc.). So you end up with a "fin" of tabbing. Then you screw that to the furniture (which is not structural anyway). As such there is no worry about bonding to Decraguard, and things are removable/replaceable by undoing the screws (yet there is no penetration into the core).

I did something a little different (and less messy). It was a bit of an experiment, and if it doesn't work out, I can easily go to one of two "Plan B's" with no more work than I would have had originally. What I did was buy slightly larger, stainless steel angles (instead of the mild steel ones that were there). I removed the original angles, overdrilled and filled the holes into the core, and chiseled them off flat when in the green stage. Then I bonded the new angles to the sole with thickened epoxy. After that had cured I screwed their upper legs to the cabinetry.

The place I think that might conceivably fail is in the bond to the sole. If that does happen I will move to one of two "Plan B's." One would be to screw them to the sole into the epoxy plugs; or two would be to remove them and do tabbing as described above. Either of those would eclipse any "failure" of the way I did it already (and again, not structural). So far so good with Plan A, but it's early days yet.

 

[thataway]

One thought if you are going to tab: As Thataway said, it can make it a pain to remove any cabinetry. Not that you are going to do that every day, but why remove the option ('course you could always cut tabbing, but...). Also, I'd be a bit "meh" on the idea of bonding tabbing to the top (white) surface of the Decragard (you could cut away the top layer, but that's more work again). So if I were going to tab (and I may in some places), I think I would do it how I have seen it done on Albin boats (just for one example). Essentially, you lay up the tab and bond it properly to the hull (sole) as you would normally tab. But, you don't bond it to the "furniture." Instead you lay it up against the furniture, but keep it from bonding (tape, wax, etc.). So you end up with a "fin" of tabbing. Then you screw that to the furniture (which is not structural anyway). As such there is no worry about bonding to Decraguard, and things are removable/replaceable by undoing the screws (yet there is no penetration into the core).

The most common way to secure furniture (either wooden or fiberglass) to a fiberglass hull is to tab it in. This is a well proven technique. It is not "messy" as Sunbeam implies. If you want to remove the tabs, it takes less time to cut it with a grinder than to remove even one of the screws into the hull. It is far faster (and can easily be incorporated into sealing the holes in the hull) than the drill out, undercut, make an epoxy plug etc. Why make something complicated when there is a well proven and excellent method available? Both of my 22's and the 25 had some rust on the steel "L" brackets along with some rust of the screws. Granted there was no significant core damage, but with time there can be. Then it gets very expensive and difficult to repair.

 

[journey on]

Just out of curiosity and to keep from doing something useful, how are the one piece interior moldings now used fastened: brackets or tabbed?

Seems tabbing would be quicker and probably more secure.

Boris

 

[ghone]

Hi Boris. My 2011. 22 has the molded interior. It is bonded full lenth to the hull, up the back bulkhead, where it meets the hull sides etc. ie. all the way around the galley part and dinette parts and floor.etc Not tabbed, but full length bonds. This makes for a very rigid cd 22! I was impressed on delivery, they could have done short tabs.
George

 

[Sunbeam]

The most common way to secure furniture (either wooden or fiberglass) to a fiberglass hull is to tab it in. This is a well proven technique. It is not "messy" as Sunbeam implies. If you want to remove the tabs, it takes less time to cut it with a grinder than to remove even one of the screws into the hull. It is far faster (and can easily be incorporated into sealing the holes in the hull) than the drill out, undercut, make an epoxy plug etc. Why make something complicated when there is a well proven and excellent method available?

Okay, I clearly either need to get better at writing what I mean, or post a lot less. Geez, embarrassing. I'll watch myself in future posts. So, to try to clarify:

1)I do find executing proper tabbing to be a bit messy, myself. I mean, sure, if you have a project going already, it's just part of it. But if your boat is in "house mode," and you start sanding and fiberglassing, it can be a bit messy is all. That said, careful prep and protection can keep the mess down, absolutely. I do this often: Tape up plastic, have a vacuum going, work neatly. So perhaps I should not have said fiberglassing was messy.

2) I have nothing against proper tabbing, and have laid dozens of yards of it in other boats. It is simple to remove or cut through it with a grinder or Multimaster. I liked the "Albin style" tabbing idea on the C-Dory for a couple of reasons:

a) The furniture would still be removable (by undoing some screws) and then replaceable (put them back).

b) No worries about adhesion to the Decraguard and/or having to sand or cut off the top layer (I have often done this on plywood that has a thin surface veneer, because otherwise you're only tabbing to that fragile layer).

So my idea was to lay up the "fin style" tabbing that Albin does (it is properly bonded to the hull, but not bonded to the furniture - it is screwed to the furniture). But again, nothing against "full" proper tabbing! Especially on structural items (this furniture is not structural however).

3) Everyone doesn't need to do the projects on their boat that I do on mine, and if they do them, they surely don't need to do them my way. I just know that when I'm thinking about a project, I like to hear many different opinions and ideas, so I thought I'd post mine. I don't mean to imply that others are doing things wrong, that they need to worry about anything, or that they should do anything I do, or how I do it.

Again, sorry if I misled anyone. Tabbing is great. C-Dorys are great. And I'll try make fewer such posts in future; it's embarrassing and I should be a better writer than that.

 

[Lost Petrel]

I am going to go with Sunbeam on this one. I have done some refitting on boats and now try and create a solid tab that the cabinetry can be screwed to/through. The main reason is if I have to someday remove the cabinet to run wire or hoses, etc., it is a lot easier job requiring a lot less tools and time.

 

[Sunbeam]

I figured I'd post a photo of what Lost Petrel and I are referring to. This is an Albin Vega (sailboat, but they did this in powerboats they built as well), with the bulkheads out, but the tabbing "fins" still in place. (One happens to be white and one natural "glass" gold color). When the bulkheads go in, they are set flush to the "fins" and then screws go through the fins and into the bulkhead (or furniture).

This is arguably not as strong as full tabbing (fiberglassing to both surfaces), but it seems to have held up pretty well in these structural bulkheads, so in non-structural applications it should be completely fine, in my opinion. Just another way to do things.



In my case if I were going to make some of these "fins" of tabbing in my C-Dory (in place of the metal brackets), I would likely do something like put clear packing tape on the furniture (where the tab would land) and prep the hull for fiberglassing as per usual, then "tab" to the hull and up onto the clear tape. Once the glass had cured I'd loosen the furniture piece in question and pull the tape, then screw the remaining "fin" of tabbing to the furniture (as the angle brackets are) once it had fully cured. It's one way to tab the furniture in place but also keep it reasonably easily removable, if one so desires. Just one way of course, and simply a choice.

Sunbeam

 

[Sunbeam]

Too late to edit, but I should have mentioned I wouldn't make such comprehensive (long) tab "fins" as in the photo to fasten non-structural cabinetry/furniture in a C-Dory. Just short tab sections would be plenty, in my opinion. Those in the photo are for structural bulkheads, whereas the C-Dory furniture is basically "being held in place."

 

[Sunbeam]

Hi Boris. My 2011. 22 has the molded interior. It is bonded full lenth to the hull, up the back bulkhead, where it meets the hull sides etc. ie. all the way around the galley part and dinette parts and floor.etc Not tabbed, but full length bonds. This makes for a very rigid cd 22!

I had seen that the molded furniture was bonded in place somehow on a friend's 22, but I didn't realize it made the boat more rigid (than any other 22) since I didn't think the "furniture" moldings were more than just thin fiberglass "shells." (Not that thin fiberglass can't be strong, but I mean I didn't think this was that type of setup.) I was thinking that the bonding was just the way they used to "attach" the furniture vs. providing structural support.

I'll have to look at one more closely when I get a chance at a get-together or etc. I had only just looked at a few in passing when I was boat shopping.

PS: Perhaps the furniture is bonded to the boat with methacrylate? I know that (at least in 2012 when I stopped in at the builder and they showed me), the cockpit liner and various other linery things were held in place with methacrylate adhesive.

 

[thataway]

I'm wondering if i need to worry about the screws that secure the cabinet to the hull floor and other screws in the area that are the holding potable water line secure etc.... They do not look like they were sealed and I don't want to have any hull rot

Before we get carried away too much--this is a simple question with a simple answer: The penetration into the core needs to be removed, and filled. How it is attached later is a choice.



This is a quick fix, as was done in the screws in the 25 I owned. I over drilled the screw hole, made sure the core was dry. A quick sand in that area, filled the screw hole with MarineTex, and then while that was still tacky, put on a piece of triaxial up on the side of the DecraGuard, and down over the bottom of the boat. All done in a matter of minutes.

Not all Albins are built with single tab;screwed bulkheads--and this has proved to be the downfall of some of the boats. I would never build an ocean going boat with this method for a number of reasons. As for removing the furniture in a C Dory 22--unless you are gong to extensively modify the boat, there is no reason to do this for running wiring or hoses. In the 25 and Tom Cat, I immediately ran 1/8" dacron line thru areas where I wanted to pass additional wiring, to allow it to be easily pulled. A properly built boat will often have chases for wiring and hoses. I find that PVC pipe makes an excellent chase molded in when the boat is built.

Using "Plexus" glue, is a well accepted method of putting in fiberglass liners. Certainly the fiberglass furniture/liner will stiffen up the boat. As we use our boats often we notice that some parts do work in the 22, and under some conditions the hull torques. The "V" berth and head platform in the 22, are tabbed fully into the hull, as is the aft bulkhead. This does add significant stiffness to the boat, and are essential. In some boats this was not done properly and there has been occasional breakdown of the tabbing or voids which were left, and allowed rot in the cored structure of the aft bulkhead.

 

[rogerbum]

When I was getting ready to sell my 22, I took the time to remove all the screws that held down the cabinetry. I had water in the cabin a few times and as a fisherman I often track water in on rainy days. I found the screws to be mostly dry after 8 years of use but there were some areas immediately adjacent to the screws that were moist. I got to dry wood in all cases with just a little bit of undercutting. All of the brackets on the floor were pretty rusted after 8 years. I took Bob's advice at the time and just tabbed in the cabinetry. I think very few people will ever actually remove the cabinets and if they do, it's usually for some fairly major modification. So IMHO, tabbing them in on both top and side makes the most sense. It's fast, it's easy and it's strong. With a dremel and cutting wheel, the tabs can be easily cut in seconds. If you repaint the cabin sole, the tabs look pretty decent too. Here's one I did inside of the galley cabinet. This view is looking down, the bracket you see if off the floor by a couple of inches.

 

[CDory23]

Thanks for all the replies. The tabbing looks like a good option. I am very limited with knowledge of fiberglass fabrication/repair at this point. How well does the decreguard and cabinetry need to be sanded before applying cloth and resin? Luckily I have a tap plastics near me with access to all materials.

Also this only eliminates the cabinetry L brackets and screws. What about all the screws holding the potable water line is place?

I understand the process of overdrilling/undercutting, but on other posts I have seen the use of two epoxies to fill holes, is that necessary?

Thanks again

 

[Sunbeam]

Also this only eliminates the cabinetry L brackets and screws. What about all the screws holding the potable water line is place?

I eliminated those holes at the same time as I did the brackets, for two reasons:

1) I didn't want any holes into the core - just didn't seem necessary.

2) I didn't like having the water lines attached to the sole because it made it hard to clean/crud could get trapped under them.

At the same time, I re-routed one of the lines. On my boat I have a foot pump at the galley sink, and the supply line for that ran along the inboard edge of the galley cabinet, then made a sort of an "out and around" loop on the sole to meet up with the hose barb on the pump at the correct angle. Since I was replacing all the lines with new hose anyway, I ran that line around the outboard side of the galley locker. Takes a little bit more hose but now it's out of the way and the stowage area is not bisected by a hose.

By slightly moving the P-clamps I was easily able to attach them to the cabinetry instead of the sole. So no holes into the hull and also they are less prone to trapping dirt.

I understand the process of overdrilling/undercutting, but on other posts I have seen the use of two epoxies to fill holes, is that necessary?

Typically it's not really two epoxies, but rather the initial "coat" is neat (plain) epoxy. Reason for that is it bonds better to the core than thickened epoxy would. But if you make a larger "hunk" of it, it's brittle. So what one typically does is stir some thickener powder into it (this strengthens it in addition to making it thicker in consistency) and then use that to fill the bulk of the hole. If you work efficiently you can even use the same batch (neat, then thickened).

On the other hand, you can use the pre-mixed WEST 610 (thickened epoxy with somewhat variable viscosity) for the whole shebang (WEST say). I still tend to use regular neat epoxy for the first "wet out," but theoretically you can use the 610 for both. "Pound for pound" the 610 is very expensive, BUT it's very efficient and tidy to use, and these sorts of filling jobs don't typically take gobs of it. It has definitely become "standard stock" in my epoxy kit. I still keep "traditional" (ha, who ever thought you'd be able to use that word to describe epoxy) plain epoxy and fillers on hand, but then I've been using it on various boat projects for some years, so they are just part of the project arsenal (the 610 isn't ideal for everything).

 

[thataway]

I do not feel that it is necessary to use "two" epoxies. What you can do is to take a "Q" tip and dip it in the epoxy after the two parts are mixed, before adding the thickening agent to coat the hole, this takes a few seconds. (See my note about the migration of what Sunbeam calls "neat" epoxy vs one of the low viscosity epoxies [such as Clear Penetrating Epoxy Sealer--CPES], which migrates far better into balsa core than one of the usual laminating epoxy, such as West 105.)

You should not add thickening agents until you have mixed the epoxy, so there is no extra step. The epoxy has enough pot life to allow this and then thickening, and further use.

I recently put a Jabsco galley pump, in the water line from the water tank before the foot pump (it allows water to flow thru, with minimal loss of volume. I did not use their switch or spout--kept the old one). This was to empty the water tank at the end of the season, or when shocking it. There is a monetary switch, which can be pushed with a finger or kept down with knee pressure, on the face of the galley cabinet.

I filled the "C" clamp holes and left the hose loose as Sunbeam described.

 

[CDory23]

Ok, So I have removed screws and drilled overdrilled holes to 5/32. I placed a piece of tape on the bit to not go too deep but i noticed one hole is about 5/8" deep. I have also bought "Smiths" CPES.

Do i need to be concerned with the one hole that is 5/8" depth? Was my diameter that I overdrilled large enough? Also for the undercutting what bit is the best to attach to the dremel? A routing bit?

Thanks.

 

[Sunbeam]

Ok, So I have removed screws and drilled overdrilled holes to 5/32. I placed a piece of tape on the bit to not go too deep but i noticed one hole is about 5/8" deep. I have also bought "Smiths" CPES.

Do i need to be concerned with the one hole that is 5/8" depth? Was my diameter that I overdrilled large enough? Also for the undercutting what bit is the best to attach to the dremel? A routing bit?

Thanks.

On my boat (2002 22 Cruiser) the main hull has coring of at least 1" thick, so I think you are fine. I'm not saying you should get risky, but I find that if I am careful drilling, and "feel my way" that I can tell when the tip of the drill bit touches the solid glass on the other side of whatever core I am relieving. Hence I usually go right to glass (but not into it).

I tend to use four tools about 90% of the time when digging out core (although I have an arsenal of possibilities, and use whatever works). Those are the Dremel #115 bit, the Dremel small sanding drum (sometimes works better than the metal bit, counterintuitively), a dental pick, and a small flat-bladed screwdriver. The pick will get into very small holes (Dremel requires something like 5/16") and really "catch" the core and bring it out (a vacuum helps too).

If I can, I "clean up" the inside of the outside skin (i.e. bottom of hole) for better adhesion, although it's not a big deal in this case. But I just mean I try to scrape the core off, vacuum, and then eliminate dust before epoxying.

Although there is no need or desire to cut out great swaths of the top skin of fiberglass, I don't have any issue with going to a 5/16" hole to make the process easier and get a larger annulus. But each situation/person/job is a bit different. There are times I've done the digging through a tiny hole (maybe in a case where I don't want it any larger cosmetically); but I usually go a bit larger than 5/32" just for access.

 

[CC Rider]

I am going to be adding shelves and possibly some drawers to my galley under-sink storage area this winter, and the elimination of the rather cheesy factory-installed, screw-into-hull steel L brackets is one of my targets.
This may be a dumb question, but I was floating the idea of using 3M5200 to bond a piece of marine plywood to the hull to act as a cleat. The cleat would be about an inch or so in height. Then, screw through the cleat to the cabinet side.
Is the use of 3M5200 for this purpose ill-advised?

Chris