McCall Boat Works 3M5200 Bottoms ONLY!! Here's Why!!

It's A New Woody Day!!

Today I would like to educate you on why MBW restores the bottom of boats with a 3M5200 bottom.
This question is asked to us A LOT:  hopefully, this will clear up some of your questions:

First........ a little history.....
Nearly all the boat manufacturers from the 1920-1960s constructed their bottoms to last approximately six to eight boating seasons.  Even with the best maintenance, thru time, most have lurking problems underneath the surface where it’s not visible to the naked eye.
McCall Boat Works has put on many bottoms.  Time after time, upon first examination all appears fairly well….............tight seams, good paint, no exposed fasteners, no cracks, soaks up in a couple of days, etc., etc. However, if one is willing to get a little dirty by climbing into the bilge with an ice pick and flashlight and do some serious poking around ................a whole new view point can be viewed...........ugh!!

Many bottoms' most prevalent problem areas are loosened, broke, or bent fasteners (they are after all, soft brass).
Other common areas of trouble are bottom plank cracks following the fastener lines where screwed into the frames…......again from the planks expanding and contracting over the years. Cracked and/or pushed out chines due to excess pounding and excess debris in the bilge, cracked bottom frames, and more often than not festering rot in the canvas between the inner and outer planking…where you can least likely see it.
The two areas most damage occurs is about 1/3 amidships (close to the front seat) where the boat takes most of the pounding, and again near the transom where water likes to sit and spore rot over time.

Unfortunateney, many of these boats have old, and incorrect remedies:  caulk or linen to fill the plank seams in order to get a ‘tight’ fit and stop the water from coming in. Also used were hard epoxy products to fill the seams.
All that these ‘fixes’ do are create and many times enhance the current problems............. by furthering the expansion of planks against planks against very tired fasteners..............…resulting in an even worse bottom..........
But, ALL this remains hidden until the bottom planking is removed.

"Let's bring on the 5200 Bottom" which basically includes the CPES sealer, the 3M5200 and the silicone bronzed fasteners.

It is put on like a thick like paste then spread to a consistent layer with a trowel.  It remains flexible like rubber when cured.  If done properly, the 5200 will ooze between each adjoining plank seam to make a watertight, yet flexible fit.
WOW!!
It’s also important to remove, clean (replace if necessary) the bottom transom plank along with the hullside chine planks.  These planks will be under the water along with the bottom. It is important to reattach those planks with 5200 to make both a watertight and flexible fit. To do the bottom and ignore those planks will still allow water in the bilge. It’s also important to remove and reseat both the rudder and shaft log assemblies in 5200.
WWAAAALLLLAAA!!!
That’s it!!  It’s hard and messy work, and takes a lot of time to do it correctly. When finished, though, you will have a bottom that will not leak and will out-live everyone involved.

Why 5200 and not hard epoxies?
Wood is always moving—expanding and contracting with moisture levels and temperature…not to mention the natural movement as she pounds through the water. If the wood is always moving and hard epoxies do not, what happens? You end up with cracks in the epoxy and/or wood tearing from the epoxy as it comes under stress. This is obviously not good for the boat, resulting in even more damage that you started with.  Don't do it!!
The 5200 is flexible and thus flexes and moves with the wood, eliminating stress cracks while it continues to maintain its water tightness.
Finally, the 5200 system bottom will increase the value of your boat by the amount invested in it!!  It's a win-win situation for all!!  Ask any boat broker and they will tell you boats with properly done 5200 bottoms will bring anywhere from $8,000-$12,000 more depending on the size and model of boat.
Additionally, you will NEVER have to worry about having to soak your bottom again. Your bilge will always be dry (except of course if you get rained on). Pull her out of the water and you’re done.

In the end, the 5200 system properly replaces the bottom of your boat, protects it from future rot due to sealing, flexes with your boat, provides the same ‘wooden ride’, looks original, allows more freedom in keeping your boat out of the water, and increases the value of your boat significantly. Need I say more?  You decide.

The short story is:  a ‘5200 bottom’ is where you remove the current bottom, make repairs or replace damaged frames and chines, tighten and/or replace all frame bolts....then use new mahogany planking supported by marine grade plywood as the inner layer sealed in a proper and flexible wood sealer. The new lumber is attached with silicon bronze fasteners and 3M 5200 adhesive. The 5200 product comes in a caulk tube which is applied to the inner layer (marine grade plywood) before attaching the outer mahogany planking.

First, is removing all from the boat to include engine, chrome, upholstry, fuel tank ect. and rolling her over to "bottom's up" position and the bottom is removed. Much care is taken to ensure the planks come off in one piece so they can be used as patterns. They are marked for placement and set aside for later. The frames, chine, and keel are checked for cracks and/or soft spots. Damaged frames are replaced, unless the damage is minor in which case they can be repaired. The frames and inside of the chine and keel are then sanded to bare wood, sealed with CPES and painted with thinned bilge paint.

The inner ply layer is then dry fitted using Marine-Grade plywood.  The plywood is "scored" to match the original interior diagonal planking.

The wood is sealed with CPES and allowed to cure overnight. A bead of 5200 is applied to the frames, and then the ply is attached using stainless staples. Intermediate frames are actually attached to the inside of the ply during this process to help facilitate a tighter fit for both the diagonal ply and then the outer planks.  On some occasions steaming is required to get the proper bend.

The next day a liberal layer of 5200 is applied with a pneumatic caulk gun, troweled over the ply, one plank strake at a time with another bead along the leading edge of the prior plank and the butt joints. All planks are attached with silicon-bronze fasteners, starting with the bow plank and following with the stern plank. We begin at the keel and work towards the chine. The excess 5200 that oozes between the planks is scraped off with a putty knife and wiped smooth with a rag soaked with Acetone, cleaning the remainder of the plank at the same time.

We allow the 5200 to cure five to seven days.  After curing overnight we apply a two-part epoxy primer base paint prior to the final two coats of bottom paint.

Your bottom will look like this when complete.

WOW!!!!!!!

During this process we also check the carriage bolts, re-seat both the rudder and shaft stuffing box assemblies in 5200, repack them, and repaint the bilge up to the waterline. The chine hull side plank is also removed, cleaned, sealed with CPES, and reattached with 5200 to assure a watertight fit up to the waterline.

I hope you have learned something!!

Happy Boating!!