Construction Approach for Miscellaneous Boxes, Etc.

This is the place to post your ideas, thoughts, questions and comments as relates to general boatbuilding and reconstruction techniques and procedures (i.e. recoring, epoxy, fiberglass, wood, etc.)
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RUSSELL
Bottom Sanding Grunt
Posts: 3
Joined: Thu Sep 15, 2011 1:29 pm
Boat Name: Sweetpea
Boat Type: 1978 Catalina 30

Construction Approach for Miscellaneous Boxes, Etc.

Post by RUSSELL »

I am about to begin construction of various boxes and supports to hold different items as part of the overhaul of my Catalina 30. An example is a battery box for the engine starting battery.

These items will all be inside the hull; not exposed to the weather. They will not be in the bilge, and "should not" have water on them. I say "should not" because leaks seem to perpetually fight back, and at some time water will be on the surfaces of the items.

My tentative approach is to construct the item out of plywood, rounding corners as much as possible. The plywood strucrue will then be painted with epoxy, corners layered with a mix of ground fiberglass and epoxy, and then covered with six layers of fiberglass cloth and epoxy. The various structures will then be glassed to the fiberglass body of the boat using the same approach (i,.e, following cleaning and grinding of the boat body, painting with epoxy, and filling in with a mix of ground fiberglass and epoxy I would then use mutiple layers of fibergalss cloth/roving and epoxy to fix the structure to the body of the boat).

I reason that this will be a solid approach because the items "should not" be wet. They will be covered with multiple layers of cloth and epoxy, which should resist the short periods they do get wet. I will paint the final installation with an epoxy-based paint (different paints for different uses).

Does anyone who has been down this road before see any weakness in this approach?

Thanks!
ILikeRust
Skilled Systems Installer
Posts: 285
Joined: Tue Oct 19, 2010 8:22 pm
Boat Name: Grizabella
Boat Type: Pearson Wanderer 30
Location: Richmond, VA

Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by ILikeRust »

SIX layers of fiberglass for a box that will be inside the boat???

Seems like way overkill to me.

I just built a new battery box for my 1968 Pearson, and a new bulkhead for in front of the engine. Both are made of a combination of solid wood (ripped and planed from standard construction-grade 2x lumber) and plywood, all of which I coated well with clear penetrating epoxy sealer and then several coats of Rustoleum paint. You can see both here:

Image

It's not going to be submerged, as you observe, and it shouldn't even really get all that wet, if at all. Seal it with epoxy, maybe reinforce corners with a little thickened epoxy and if you really want, a strip of fiberglass, and keep it well painted.

I see no need to build up layer upon layer of epoxy and fiberglass for something like an interior box. Seems to me that would make it unnecessarily thick, heavy and clunky.

Just my humble opinion; YMMV.
Bill T.
Richmond, VA

"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible." - T E Lawrence
RUSSELL
Bottom Sanding Grunt
Posts: 3
Joined: Thu Sep 15, 2011 1:29 pm
Boat Name: Sweetpea
Boat Type: 1978 Catalina 30

Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by RUSSELL »

Thanks - I don't really know how to go about these things and so my initial plans are sometimes (usually) overkill. My reasoning is that most of the time you can't overbuild things, and if I do more than needed I won't have problems in the future. No need to waste supplies, however.

Appreciate the feedback - why I asked.
ILikeRust
Skilled Systems Installer
Posts: 285
Joined: Tue Oct 19, 2010 8:22 pm
Boat Name: Grizabella
Boat Type: Pearson Wanderer 30
Location: Richmond, VA

Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by ILikeRust »

You should have seen what passed for a "battery box" that was in there before I tore it out and put in the new one. If that can last for several years (which it evidently did), mine should last for 30.
Bill T.
Richmond, VA

"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible." - T E Lawrence
Surveyor
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Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by Surveyor »

Russell,

If you havent already, take a look at some of Tim's projects on the following page:

http://www.lackeysailing.com/logs.html

There is a tremendous amount of information there and it may be too much to digest in one sitting. I can guarantee that you will learn many things that you are going to need though.

I have looked over every project Tim has featured, some twice, and I feel that I have learned more there than from all of the books I have read on the subject of boat repair.
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Rachel
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Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by Rachel »

I may be "stepping back" further than you want to go with this topic, but in planning out a battery box installation (if that's not all planned yet), you might want to consider the ABYC standards. These are guidelines, not laws, but they are often useful in pointing out things that would make a given installation better.

If I were going to build a battery box and then put six layers of fiberglass on it, I think I would be tempted to simply make it of pre-made fiberglass board, tabbed into the boat. I would at least consider it as an option before I proceeded.

Not that you want any installation to be weak, but if you are going to be doing any boisterous sailing it's really important to fasten them such that they don't have any chance to move around (probably obvious, but I have seen a lot of marginal installations, or ones that seem to assume a sailboat will remain perfectly upright at all times, batteries will never leak, etc.).

I don't have access to the most current (2011) version of ABYC's battery/installation standards, but here are slightly older ones.

E-10.7 INSTALLATION
E-10.7.1 If the mounting surfaces of components of the boat in the immediate vicinity of the battery are of a material attacked by the electrolyte, a mounting means shall be provided that is made of material that is not damaged by electrolyte.

E-10.7.2 Provision shall be made to contain leakage and spillage of electrolyte.

E-10.7.3 Fasteners for the attachment of battery boxes or trays shall be isolated from areas intended to collect spilled electrolyte.

E-10.7.4 Each installed battery shall not move more than one inch (25mm) in any direction when a pulling force of 90 pounds (41kg) or twice the battery weight, whichever is less, is applied through the center of gravity of the battery as follows;
E-10.7.4.1 vertically for a duration of one minute, and
E-10.7.4.2 horizontally and parallel to the boat's centerline, for a duration of one minute fore and one minute aft, and
E-10.7.4.3 horizontally and perpendicular to the boat's centerline for a duration of one minute to starboard and one minute to port.

E-10.7.5 No battery shall be installed directly above or below a fuel tank, fuel filter, or fitting in a fuel line.
NOTE: This does not prohibit a battery from being installed directly above or below an uninterrupted fuel line. However, if a metallic fuel line is within the 12 inch (305mm) envelope of the surface of the battery, it shall be shielded dielectrically as required in E-10.7.8.

E-10.7.6 Batteries shall not be installed directly below battery chargers or inverters.

E-10.7.7 To prevent accidental contact of the ungrounded battery connection to ground, each battery shall be protected so that metallic objects cannot come into contact with the ungrounded battery terminal and uninsulated cell straps. This may be accomplished by means such as;
E-10.7.7.1 covering the ungrounded battery terminal with a boot or non-conductive shield, or
E-10.7.7.2 installing the battery in a covered battery box, or
E-10.7.7.3 installing the battery in a compartment specially designed only for the battery(s).

E-10.7.8 Top Terminal Battery - Each metallic fuel line and fuel system component within 12 inches (305mm) of a battery terminal, and above the horizontal plane of the battery top surface, as installed, shall be shielded with dielectric material to protect against accidental short-circuiting.

E-10.7.9 Side Terminal Battery - Each metallic fuel line and fuel system component within 12 inches (305mm) of the terminal side of a side terminal battery shall be shielded with a dielectric material to protect against accidental short circuiting. If the battery has side terminals, the horizontal plane shall be considered to begin below the side terminals. See Figure 1.
NOTES:
1. Terminal insulation or battery covers do not comply with this requirement since, during installation or removal of a battery, these protective devices are usually removed in order to connect the cables.
2. Any non-conductive material may be used for shielding as long as it is durable enough to withstand accidental contact by a tool or the battery terminals during servicing, installation or removal.
E-10.7.10 A vent system or other means shall be provided to permit the discharge from the boat of hydrogen gas released by the battery. See ABYC H-2, Ventilation Of Boats Using Gasoline.

E-10.7.11 Battery boxes, whose cover forms a pocket over the battery, shall be vented at the uppermost portion of the cover.

NOTE TO E-10.7.10 and E-10.7.11: These requirements also apply to installations of all batteries whether they employ removable vent caps, non-removable caps, are "sealed" or "maintenance free" batteries, or have pressure regulated valve vent systems with immobilized electrolyte (gel batteries).

E-10.7.12 Batteries shall be charged by means of an automatically controlled device, that is capable of supplying the current and voltage appropriate to the type of battery being charged. See ABYC A-20, Battery Chargers, and ABYC A-25, Power Inverters.
RUSSELL
Bottom Sanding Grunt
Posts: 3
Joined: Thu Sep 15, 2011 1:29 pm
Boat Name: Sweetpea
Boat Type: 1978 Catalina 30

Re: Construction Approach for Miscellaneous Boxes, Etc.

Post by RUSSELL »

Thanks to all. The ABYC reference was most helpful. I expect to work on this over the weekend - I'll see what I can do.

Thanks!
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