1959 Chris Craft: How to Install Bottom Planking When Fabricating a 5200 Bottom

1959 Chris Craft fabricating 5200 bottom

I have had several requests for a video showing our crew installing the bottom planks into a bed of 3M5200.

Here it is. Using the 1959 17’ Chris-Craft Sportsman as our “lab rat,” John and RJ share some of the tricks we have learned that help us ensure a complete seal between the planking and the plywood outer skin, and, what in some ways is critical, that the 3M5200 ends up where we want it without suffering hours of misery cleaning the 5200 off places it does not belong – in countersinks, oozing between the planks, and – horror of horrors, dripping down the topsides.

First and foremost, as Danenberg urges to all who will listen, scrimping on the 5200 translates into a shortcut 5200 bottom that will not last. Lay it on … thickly. We lay down at least 1/8” to 3/16” of the goo. Yes, that translates into a huge number of very expensive tubes of 5200, probably at least 60 for the layer between the inner plywood skin and the bottom planks in this case of this 17’ hull. And, yes, you will end up removing lots and lots of the stuff where it squeezes out through the seams. But, as is so trite, but also so true, price and cost diverge quickly here. A proper 5200 bottom means investing in mountains of 5200. Do it right, however, and you have a bottom that will last many decades. Take the shortcut route and, well, you might well experience the pain and suffering of removing a failed cheap alternative.

And, not Life Caulk, which is fantastic when used for its intended applications, cannot be substituted to save money. It’s cheaper now for sure, but oh so much more expensive in the long run.

We use blue painter’s tape to keep the 5200 away from adjoining planks and also the surface of the plank being installed. You will see how in the clip.

We learned the hard way what a disaster we and you will have on your hands if the 5200 pushes up through empty pre-drilled fastener holes. The silicon bronze fasteners, the drill bit, the disposable gloves, and the plank’s surface end up hopelessly befouled by 5200. Yes, it can be cleaned using Interlux Brushing Liquid 333, but why put this horror show on you when a technique John and RJ developed absolutely ensures no fountains of 5200 rising through fastener holes?

As with so many super creative and completely intuitive solutions, this one is trivially simple. Sink a fastener in each hole, but stop just short of driving it home. The fastener head will have seated in its countersink just enough to act as a seal. No 5200 can squeeze by.

Once all of the fasteners have been sunk in this manner, a crew member begins at each end of the plank, driving them home. As is illustrated in the video, yes, there is squeeze out, and lots of it, but the escaping 5200 lands on the blue tape, not the wood, or the screws or the gloves, well, not so much on the gloves.

Once every screw has been driven home, the squeeze-out is scooped off the tape using a combination of a plastic scraper and a simple wood paint stirring stick. Having removed all of it, we simply pull the tape, leaving an almost clean surface.

Using Interlux Brushing Liquid 333, we then scrub everything absolutely clean. However, the 333 actually retards 5200 curing, so the final step involves wiping everything down with Acetone.

C’est finis!

Snake Mountain Boatworks LCACBS Varnish Buffing Workshop

how to varnish vintage boats workshop

“Always start with the least abrasive grit that will work, as you don’t want to remove any more of the finish than necessary…” (The Brass Bell, “Buffing Varnish,” p. 42. https://www.dropbox.com/s/z6hzszvd760…)

Industry Standard: 3M Finesse-it II (www.3m.com) will remove up to 1500 grit scratches, but our goal is to remove scratches down to 3000 grit. (Here is where we stopped buffing Voodoo Child, my 1953 22’ Shepherd Model 110-S.)

1. Using a 1,500 RPM pneumatic palm sander, we sand the surface using 600 grit dry paper until it looks like a field of unbroken snow.

2. Wet sand using rubber hand sanding blocks through a progression of papers – 900 1200 1500 2000 2500.

3. Wet sand using the palm sander and a continuation of ever-finer grits – 3000 5000

4. Using a variable speed electric Makita buffer and a foam waffle pad, we first buff with Mequiar’s (www.meguiars.com) Mirror Glaze, first with M105 Ultra Cut Compound, and then with Ultra Polishing Polish 205.

I will allow John and RJ to fill in the rest of the story in this flip

1946 Chris Craft Brightside U22 Major Milestone!

1946 chris craft brightside u22 milestone

Finally! She, and her previous “restorers” fought us every inch of the way. Perhaps most distressing is that, rather than neglect and just use her, this 1946 Chris-Craft Brightside U22 owners consigned her to shops for periodic maintenance.

Sadly we now know that she returned worse for wear because these folks took every shortcut and made every mistake possible. Bottom line, they worked to embarrassing low standards. Rather that repair, these incompetent souls created water traps, used softwood where white oak belongs, drove in stainless fasteners below the waterline, and on and on.

Sistering bottom frames resulted from being too lazy to simply release the keel, so that broken and rotted frames could be removed and replaced in whole, not piecemeal. Undoing all of the sloppy, ill-informed and just plain destructive results has been our prime challenge as we worked to essentially rebuild the transom and bottom framing, virtually from scratch.

Example: we replaced her rotted and split gripe because of the water traps these guys created, an issue that was compounded by not taking the time to replace broken carriage bolt fasteners. However, all of that is behind us as of today. We removed the corkscrew twist in the hull, the severe hogging caused by improper frame work, replaced at least two-thirds of the frames and cross ties, junked the replacement (softwood!) steering box mount with rugged white oak, replaced the gripe and much, much more.

Every square inch of every surface below the waterline received three coats of Clear Penetrating Epoxy Sealer (CPES) and two initial coats of Sandusky Chris-Craft Mahogany Bilge Paint. With proper maintenance over time, none of these members should ever soak up water again.

Now the hull is absolutely solid and ready for her True 5200 bottom. First, we will give the many tubes – at least 30 – of 3M5200 time to cure before we begin stressing it as we will when the inner sheets of plywood and outer planking are applied.

The sense of relief in the shop was like venting a huge boil as John tightened the final hex nut on the steering box mount.

Now the fun begins as she will look more and more like the graceful woody she is as we begin the construction (rather than deconstruction and replacement) phase of saving this wonderful and venerable Chris-Craft, who will grace Ahmic Lake in Ontario, Canada once again starting next summer!

1942 Century Imperial Sportsman: Why Filling Seams with 3M5200 Is Forbidden

1942 century imperial sportsman 3m5200 not seam filler

This morning’s 1942 Century Imperial Sportsman preservation project update is a plea, “Please, please do not pay 3M5200 into below-waterline seams.”

It is an adhesive, not caulk, pure and simple.

I have lost count of the number of otherwise wonderful woodies who arrive at the shop presenting curtains of old 3M5200 – stalactites – hanging from the bottom plank seams.

Once cured, 3M5200 will not compress when wetted planks try to expand. The result? Here is stark evidence of what happens next. The planks buckle and split, as several of them have in the ’42 Imperial Sportsman.

I have begun cleaning the seams using a curved pick and a reefing hook, supported by utterances that are for other than polite company.

As John noticed when he examined my growing pile of released 5200, “Most of this stuff never even adhered to the edges of the planks! Look at all the dirt and debris. So, not only did putting it in there buckle planks, it did not even work as an impediment to moisture infiltration!”

Right and right.

OK, what will we use in its place? I am opening seams that are up to 3/16” wide, which is at the outer limit of what it can bridge effectively, but we will use Interlux Seam Sealer for below-waterline applications. It cures, holds paint, and makes a watertight seal, but, even when cured, it never becomes hard. It compresses as the planks expand and expands if/when the planks shrink.

After applying the CPES and one coat of Interlux 2000E barrier coat primer, we will work up to three coats into the seams until they are almost fair with the planks. The wider seams may require more.

Some folks use Life Caulk for this purpose, a product I have used for bedding sailboat deck hardware, but never below the waterline, so I really do not have a view on its efficacy or appropriateness for this purpose.)

Then we will apply four more coats of the 2000E before we apply one coat of Pettit Tie Coat Primer and at least three of the deep, dark green topcoat our owner has approved. (Since she will be a trailer boat, We will likely reach for a paint like Interlux Brightside or Premium Yacht Enamel, unless we can find a gloss hard bottom paint.)

1946 Chris Craft Brightside U22 Bottom Framing Milestone in Sight!

1946 chris craft brightside u22 bottom framing

We so hoped we would have passed the bottom framing milestone by the New Year, but she just keeps fighting us.

We discovered one more broken frame/cross-tie unit – that lying directly beneath the stuffing box – during what we fully expected would be our final integrity check.

And, what we hoped would be a minor repair to the steering box mounting system morphed into a complete removal and fabricating anew when I grabbed it during the inspection, only to pull a handful of completely rotted softwood, yes, softwood, out of what appeared to be a sound block.

This block is not original, as is evident from inspecting the forward section of the starboard bilge stringer and finding empty carriage bolt holes. But now we have fabricated, sealed and bilge painted a new mounting system using FAS grade, fully 2+ inch thick white oak that is more than equal to the task at hand.

John has finished fabricating the new cross tie, and plans to finish the frame sometime this weekend. Once it is sealed, painted and in place, we can install the keel, which will be bedded in 3M5200, and that milestone will begin fading in our wake.

Next comes installing the two chine planks temporarily as guides to sending the outer edges of the new chine frames to the proper bevel, and also sanding the bottom faces of the – now seven – new frames into the proper profile.

Finally, finally, then we can begin making patterns for the 1/8 inch thick Aquatek plywood, slathering the frames with 3M5200 – at least 1/8 inch thick, and fastening it down with thousands of silicon bronze screws.

Onward….

1959 Chris Craft Sportsman Porcupined!

1959 chris craft sportsman porcupined

The how and why of filling fastener holes with glue and toothpicks

Porcupined is surely the ugliest we make each boat during preservation. RJ and I spent many an hour sinking three round, maple toothpicks, dipped in Gorilla Glue each fasteners hole. How many? We opened and inserted 10 boxes containing 1,500 toothpicks each, and two pints of Gorilla Glue while filling every fastener hole from stem to stern and waterline to keel.

Now we are assured that the thousands of silicon bronze screws we will use to fasten the planking will bite into new wood.

We allow the glue to cure for 24 hours and then shave all the offending toothpicks off the hull using our Fein Multimaster. Next comes three coats of Clear Penetrating Epoxy Sealer and the bottom will be ready for the next steps.

Ahead of that moment, however, we must deal with the holes through which fasteners are sunk and fasten the intermediate frames – the battens – in place. All 32 of them must be degreased, toothpicked, sealed with CPES and installed, bedded in 3M5200.

Even more tedious is dealing with the hundreds of holes left when we removed the ½ – ¾ inch pan head brass screws that Chris-Craft sank into the bottom planking from inside the bilge. RJ teased the tips of #10 screws into each of these holes, lest we generate a forest of 5200 stalactites hanging from the bilge.

The bottom planking, which is in superb condition and remains eminently usable, must be scrubbed and sealed with three coats of CPES, at which time we will complete installation and the modified True 5200 bottom milestone will begin disappearing in our wake.

1946 Chris Craft Brightside U22 Bottom Framing Update

1946 chris craft brightside u22 bottom framing

By this time next week we should be fabricating and installing the inner layer of 1/8” Aquatek marine plywood to the bottom.

John will first fabricate an entire set of paper pattern sheets for each of the two surfaces and transfer them to the plywood. Once each component is cut and installed to test for fit, it will be removed and all sides will be sealed with Clear Penetrating Epoxy Sealer, followed by two coats of Sandusky Chris-Craft Red Mahogany bilge paint.

Then all three of us will work together applying mahogany 3M5200 to all ribs and other landings, followed by sinking thousands of silicon bronze screws.

The fun begins once the plywood is screwed down – cleaning the squeeze out, and there should be copious amounts of squeeze out, or you have not applied sufficient 3M5200.

The mahogany planks are next, and, while we will do our best to save the original planking, it is in pretty poor shape, which will force us to fabricate new planking using the originals as patterns.

But such considerations push us way ahead of where we are now, which is all about passing the bottom framing complete milestone!

1953 Shepherd 22′ Model 110S VOODOO CHILD at the Finish Line

1953 shepherd sportsman 110s voodoo child finish line

My 22’ 1953 Shepherd Model 110-S Runabout’s preservation is so, so close to the finish line!

But, with winter setting in, her sea trial must wait for spring 2017, which means May or later. I just cannot drop her into the water at the Sunnyland (Tavares, FL) ACBS show unless and until the sea trial, and all the final tweaks and adjustments that will almost certainly follow. (The show runs March 24-26, 2017, at which time Lake Champlain’s waters are still frozen hard.)

I have decided, therefore, to enter Flyin’ By, my 1938 19’ Chris-Craft double cockpit forward special runabout in her place.

Over the winter we will have Mickey Dupuis – D&S Custom Metal Restoration in Holyoke, MA – preserve and plate all of her hardware anew.

While the hardware is at chrome, we will strip the bottom to bare wood, and refinish it as a traditional bottom. All surfaces will receive three coats of CPES, followed by the first of five coats of Interlux 2000E two-part barrier coat. The seams will then be filled with Interlux below-waterline seam compound before the subsequent four coats of 2000E are applied.

Next comes two coats of Pettit Tie Coat Primer, which will be followed by at least four coats of brilliant red Epifanes Monourethane.

The transom, topsides and decks will be carefully hand-sanded, starting out with 400 grit, before we apply 6 – 8 coats of Pettit Hi-Build varnish.

Once the varnish has cured for 30 days, we will buff it as we did Voodoo Child.

My betting is that we have some very late nights in our future!

Happy Hanukah and Merry Christmas!

1959 Chris Craft 17′ Sportsman Transom Planking & Framing Update

1959 chris craft sportsman transom framing planking

Given the evidence that it has shrunk – a very wide seam between it and the next transom plank above, I fully expected to release the bottom transom plank.

However, the prospect of first stripping bottom paint lying on my back and then releasing all the fasteners driven through the tails of the bottom planks and into the bottom transom plank was foreboding at best.

Then, when I was having difficulty with the last few fasteners, I called in, RJ, who has what he terms his “special touch” releasing buried wood screws. As the last one backed out, RJ exclaimed, “I think your plank is free already!”
And it was and is. We now know that Chris-Craft moved the final course of fasteners forward from the tails, just enough that they are driven into the transom frame’s bottom bow.

The attempt to waterproof the seam along the bottom edge of the bottom plank was attempted using the oil-permeated canvas we have all seen when releasing bottom planking. Suffice it to say that, like the stuff under bottom planking, this course of canvas had long since lost whatever waterproofing qualities it had in 1959.

When the time comes we will install the bottom plank bedded in copious amounts of mahogany 3M5200.

A combination of finding green, and therefore moisture adulterated, fasteners behind the test bungs I popped, and a ubiquitous design issue that translates into a chronic, although slow leak, we also released the next transom plank.
The issue occurs at both ends of that plank, from its bottom edge up about 2 inches. Chris-Craft originally sealed the seam between this plank and the transom frame member it lands on using the same sealer-impregnated canvas technique.

However, each of the first 3 1954-1959 17’ Sportsman models we have preserved to date tended to seep water through that joint until we bedded them in 3M5200.

Proving that even old boat guys can learn, we routinely release this plank, remove what is left of the canvas and install it anew bedded in mahogany 3M5200.

With Christmas weekend peaking over the horizon, cleaning out the bilge and then pressure washing it will not begin until next Monday.

1959 Chris Craft Sportsman – How To Release Bottom Plank Fasteners

release bottom plank fasteners 1959 chris craft sportsman

The goal here is removing fairing-compound-filled countersinks and releasing the over 1,000 fasteners driven through the bottom planking and chines without damaging the edges of the countersink hole.

We begin with a portable drill and drill bit. (We use a pilot bit because it can withstand lateral pressure without breaking.)

Why drill all these holes? The Rotabroach cutter includes a positioning, spring-loaded pin. Yes, it can position the cutter in the countersink center, but it quickly gets loaded up with residue and fails to pop out once a countersink is opened. Then it walks across the plank until you grab a vice grip, remove the cutter and clean it.

Drilling the pilot hole gives the pin someplace to go without being pressed into the cutter head.

Next clean the hole using a scratch awl, and then the Frearson head slots using a pick, and blow the hole clean with an air chuck. (A shop vacuum will work here if the crevice tool is used, but the blast of compressed air cleans much, much more thoroughly.

Grab the impact gun to which you have fitted a #2 Frearson (Reed & Prince) driver and carefully back the screw out. (The impact gun’s trigger must be feathered so that it turns as slowly as possible for the initial rotations. A portable screw gun can be used, but it is much slower.)

The mini hook comes into play for those fasteners that simply spin in the hole. Carefully work the hook under the screw head and apply a bit of upward pressure by levering against the edge of the countersink. (Yes, “unpleasant” utterances are part of this process.)

Once you have all the fasteners – which you absolutely will not reuse – safely in the recycling bucket, and have teased all the planks off the inner planking, you are ready for the next steps. In the case of the ’59 Chris-Craft Sportsman, since the plywood inner skin presents as almost new, the next step is scraping all the canvas off, cleaning the surface and proceeding to toothpicking every fastener hole in the entire bottom.

Once you have inserted 4 to 5 toothpicks dipped in Gorilla Glue, or about 5,000 in total, into all the fastener holes, and the glue has set, reach for your Fein Multimaster and “shave” the plywood. What a mess!

Time for CPES, 3M5200 and installing bottom planking!

Tools:

  • Rotabroach Cutter Kit – available at Amazon.com
  • Portable drill and pilot bitdrill bit
  • Portable drill for 3/8” Rotabroach cutter
  • Portable impact driver with #2 Frearson (aka Reed & Prince) driver
  • Scratch awl – a Stanley brand awl is available from Amazon.com
  • A mini hook and pick set like this