hot molded boats [Archive] - Woodwork Forums

docboats1955

22nd August 2005, 07:33 AM

Hello, I've just registered, and this is my first post. I recently bought a 1957 MiloCraft hot- molded runabout. The transom is totally shot, and I'm making a new one out of mahogany. I've also cut 4 inches off of the stern because of serious rot problems. I'm now going to recover the boat with 1/8" okoume at least to the bootstripe, and probably to the topsides. I'll use west system epoxy to adhere the new wood. I would like to know what everyone out there thinks of my plan, and how I might do better. Also, if anyone out there has a MiloCraft, I'd like to hear from them. Thank you very much

Daddles

22nd August 2005, 09:56 AM

I can't help Doc, mainly through ignorance of what you're trying. Have you considered using any CPES in there? It's got a good reputation ... as well as owning a lot of myths. I'm sure there's someeone here who can offer some real advice though (Mik, where are you?).

How about some piccies. We love boat .

Cheers
Richard

Boatmik

27th August 2005, 01:31 AM

Sounds like you are heading in the right direction - or A right direction!

Would certainly like some boat too.

Richard - what is CPES? The only thing I can think of is CRIPES and I can't see why you would interject it at that point in the conversation.

Doc, what is the main problem you are trying to overcome with the veneer?

Are you going to be applying it at a different angle from the current outside veneer? Are you going to staple it or vacuum bag or something else?

Best wishes
Michael

Daddles

27th August 2005, 12:52 PM

Oh Mik, such an admission in an open forum :eek:

CPES - it's a yankee product, similar to Shipways Wood Preservative. Basically, it's a very thin epoxy designed to soak right into the timber. Won't glue anything together. They were marketing it at one stage as a rot repairer - make the rot better than new. A heap of people jumped on the bandwagon and all of a sudden, there's this magic super product that would fix all rot ills. Part of this was the way they marketed it, a lot of it was people not understanding it and making wild posts on internet forums. In reality though, it's just very thin epoxy, but thinned by the manufacturer using carefully selected thinners rather than some back yarder pouring acetone into his thick goop. It has a good reputation as a sealer, ie a base for your epoxy sheething or paint because it does seep in a long way, but it's also frightfully expensive in the wrong areas. Here in Adelaide, I'd just go for Shipways and I'm sure there are lots of other companies doing the same. I only mentioned CPES in my post because I thought it was a name more easily recognised.

Cheers
Richard

Boatmik

28th August 2005, 03:50 AM

Epoxies and thinners

Howdy Richard! I will admit to anything!

Generally the thinners based products were a precursor to the full high solids epoxy catastrophe (and I mean that in the most positive sense). The most common in Oz is the dear old Epicraft Everdure which we all used to seal the insides and underdecks and often under the paint of our racing dinghies in the seventies and very early 80s.

With racing dinghies weight is seen as somewhat critical - an extra pound or two is considered a catastrophe. Anyway, everdure was not particularly effective at keeping the water out of the timber - the boats would still put on weight - this could range from a pound or two up to about 5% of the hullweight. The reason as far as I have been able to gather is that the thinners are quite long complex molecules and as they come out of the epoxy matrix they leave holes behind.

As the thinners content of Everdure is very high - about 70 percent from memory the holes are very extensive.

Water molecules are somewhat smaller than the organic molecules so have little problem going up the same holes and into the wood.

When WEST first came on the scene (there were other good quality epoxies around at the same time - like the OZ bote cote and a few others ) it first gained popularity in the Tornado catamaran class, initially in America, where finally it was possible to build boats that took up very little weight during the sailing season. At the time it was very much preferred to build in plywood as it provide a much stiffer boat for the same weight compared to the solid fibreglass alternative that was allowed under the class rules. Later on foam/glass sandwich boats were allowed which can be built stiffer still in many cases.

The good quality epoxies are termed "high solids". This basically means that there are almost no thinners added, so there are no wormholes from the exit of thinners from the matrix - so little opportunity for water to get in (and not even much exchange of air - no water, no air, no life - thus no rot if the job is done properly - all surfaces sealed with 'pox). This comes with a significant labour and materials cost, but has a good track record in general.

One way to quickly test if your epoxy is high solids is to sniff it. There should be no intense thinners type smell. Usually the hardener has a slight ammonia smell, particularly if you have just taken the top off, but there should be nothing to make you gasp or that has a thinners type smell.

So West, Bote Cote, System 3 and some others are high solids. Many of the "Industrial" epoxies that are available at cheaper rates have thinners added - so won't keep the water out as effectively.

If you contact Epicraft and ask them about the best method to protect your boat from rot they will sell you their high solids epoxy system - because they know it is the most effective way of dealing with the problem. If you start talking about the expense they will be happy to sell you dear old Everdure and will wish you well as you depart.

The University of Queensland did mechanical testing about a decade ago on a wide range of the epoxies available at the time and it showed that in terms of tensile strength, impact resistance and work to fracture that you really do get what you pay for. The cheap epoxies are brittle and not capable of sustaining high loads, whereas the more expensive ones - Bote Cote, WEST, System 3 are a great deal better. It was certainly edifying seeing the results from the testing machines graphed. The good ones were not just 5 or 10 percent better, but often 40 or 50 percent.

There are thinners that you can add to a high solids epoxy that won't evaporate. The one that Bote Cote do is called TPRDA - which links up with the epoxy matrix and becomes a permanent part of it. Some of the other brands have similar stuff.

One other interesting thing regarding how far the epoxy has to soak in.

WEST originally stood for Wood Epoxy Saturation Technique. But as all of us who build boats know - if you cut something that has been coated the epoxy only soaks in a very small distance - a mm or less. So now WEST stands for Wood Epoxy Stabilisation Technique - which is a much more accurate description.

However this does not mean that the system is less effective because it doesn't soak in. WEST and BOTE COTE made their reputations because the stuff works. They provide an effective system for gluing and bonding timber. That effective system has never relied on soaking very far into the timber - it simply has to provide an effective bond.

You can thin epoxy to get it to soak in further for gluing purposes, but the thinners reduce the strength so much that you have made a large nett loss. They are generally not recommended for gluing applications. For coating they work, but (here we move very much more into the area of opinion - ie ... mine) I have hardly ever found them necessary.

One area where the TPRDA type thinners (whatever brand) are good is ... back onto the thread ... where a structural member or surface has a thin layer of rot. There the thinned epoxy can get in a little distance and help consolidate the area. However it does not make the timber as strong as it once was - so if the rot has compromised the structure then the strength has to be brought up to the original level. So, for example if you have a timber frame that is 50mm thick and there is a bit of rot 6mm deep on the bottom corner it MAY be OK to soak it. But if the frame is 30 or 50% rotten it needs to come out, or be sistered or a new section scarfed in.

Generally I use Bote Cote for my building, but one of the many good things that WEST have on offer is a wooden boat restoration booklet. It is really cheap - about 10 dollars and goes through all the techniques necessary to restore and repair older boats. One of the most useful things about it is that it helps you assess the structure to work out what you need to do.

DOCBOATS is using some fairly sophisticated methods so seems to know where he is going - he may not need the book. However I keep my copy handy! It should be in everyone's boatshed (read garage) bookshelf.

Gosh it's late - where did that time go!!!

Best Regards
MIK

Boatmik

2nd February 2006, 02:06 PM

For completeness I would like to post the results of some testing.

It compares the moisture uptake over time for both a high solids epoxy system and one of the penetrating epoxies.

As the graph below shows - the water uptake of timber treated with "penetrating" epoxy is about 5 times that of the Modern Epoxy solution below.

A massive 35% compared to less than 8% for the "high solids" type. (105/205 on the graph)

this is the graph
http://www.storerboatplans.com/Faq/solvent1.gif
http://www.storerboatplans.com/Faq/solvent1.gifhttp://www.storerboatplans.com/Q&A/solvent1.gif (http://www.storerboatplans.com/Q&A/solvent1.gif)
unfortunately it is a GIF file so I cant put it directly into this post.

If moisture content is around the 35% mark through using Everdure or other "penetrating epoxy" the moisture level is high enough for the timber to rot.

However if moisture is under around the 7 to 10% range it is very unlikely to rot.

The graph does show a number of different options for coating. It is generally considered that 3 coats of epoxy will keep the moisture well below the magic 10% level, but 2 coats may leave some areas a bit starved because of uneven application or "hungry" plywood.

Best Regards
Michael Storer

meerkat

2nd June 2006, 11:45 AM

Hi Mik,

the gif is no longer there, is there somewhere else I can go to ?

Regards
Andrew

Boatmik

2nd June 2006, 04:47 PM

Howdy Meerkat,

It is still on my site - but I don't know why this forum won't load it from the link.

Anyway, it is still on one of my FAQ pages.
http://members.ozemail.com.au/~storerm/Faq/Saltpreservative2.html

MIK

Ramps

22nd June 2006, 11:33 PM

What's going on?
I can see the gif are you guys blind or just using Internet Explorer:eek: (I'm using Fiefox:D and can see the gif in the post)

Boatmik

23rd June 2006, 12:02 AM

It was fixed with the help of the moderators two weeks ago Ramps

Cheers

MIK

Ramps

23rd June 2006, 01:15 AM

Arrh ... thought i was seeing things

dickstoys

23rd January 2007, 07:06 AM

Hi -
I just joined the group and read your message. I have a 15' Milocraft, met and talked to Milo back in the nid 80's and would be interested in talking to you about your boat.
Dick

Hello, I've just registered, and this is my first post. I recently bought a 1957 MiloCraft hot- molded runabout. The transom is totally shot, and I'm making a new one out of mahogany. I've also cut 4 inches off of the stern because of serious rot problems. I'm now going to recover the boat with 1/8" okoume at least to the bootstripe, and probably to the topsides. I'll use west system epoxy to adhere the new wood. I would like to know what everyone out there thinks of my plan, and how I might do better. Also, if anyone out there has a MiloCraft, I'd like to hear from them. Thank you very much

rlm

24th January 2007, 07:17 AM

Used CPES to seal the end grain on woodstrips that were overhanging my transom of a Classic Moth woodstripper. Also used it as a quick fix on another Moth where the 3 mm ply hull had checked and cracked the original epoxy finish. Just brushed it on and hoped it would ooze where it was needed. Very thin, almost water like, viscosity. Very stinky. Fellow who was lead boatbuilder on this project said it reminded him of doping an aircraft wing. Takes a while to cure. I think it does have a different forumulation than your Evercoat and it does appear to penetrate deeper in the wood. I think anywhere you have a difficult sealing job (like chainplates poking up through a plywood deck) this may be useful. As pointed out, it is not an adhesive! Whether it is any better than oil based woodsealer or thinned varnish, I'm not sure.

Rod

Boatmik

25th January 2007, 10:10 AM

Howdy RLM

And welcome!

If you follow the thread above you'll see just how poorly CPES works compared to a full solids epoxy.

The CPES smells because it is mostly thinners - look on the side of the container.

The thinners is the problem and is why the CPES fails to keep the water out any better than paint - though it can be OK at consolidating wood that has surface rot. Thats where some penetration helps.

Though there are better solutions around in that regard too - see above.

But it still should be either painted with a good system or sealed with a high solids epoxy - which is what I imagine you have done with the Moth.

Great little boat!

Best wishes
Michael

uncleremus

16th June 2007, 01:54 AM

uncleremus

16th June 2007, 01:58 AM

Hello,

I also have a MiloCraft boat, My sister bought a summer home and it was in the boathouse, I dont know anything about it but it looks great! Does anyone know where to get info on these boats?

Best Regards,

Michael

Lewy the Fly

16th June 2007, 10:36 AM

Mik,
Where does Norglass Epoxy Wood preserver fit in your graph. I was concidering using it to seal to outboard bolt holes in the transom and the eye bolt in the bow of my paulownia runabout. Am i better off running some west in there with a small brush. I thought about using both. Seal with norglass and then coat with west.

Regards

Lewy.

dickstoys

7th February 2008, 06:10 PM

dickstoys

7th February 2008, 06:17 PM

Michael,
I also have a MiloCraft boat that I purchased in the '80's and met Milo at that time.
If you still interested in additional info, let me know.
Dick

Boatmik

7th February 2008, 07:24 PM

Howdy Dickstoys,

If the information about Milocraft is not on the net at all it would be very valuable to have it here - people will be able to find it.

Or if you have information that is a bit different from what is on the rest of the net that would be fantastic too.

Best wishes
MIK

bjersey

18th February 2008, 06:10 AM

I have a 1960 18' Milo-Craft, which I have owned for 30 years. I met with Milo several times over the years at his old shop on South Western Ave in Chicago. Milo's son did a complete restoration of my boat in 1995.
How can I help?
Bob Jersey

PAR

18th February 2008, 07:50 AM

CPES (Clear Penetrating Epoxy Solution) is nothing more then regular laminating epoxy that has been dramatically weakened with several solvents, which act as a vehicle to commute it further into the cellular structure of wood.

For many years I've been suggesting it's not particularly effective used alone and recent studies have proven my assumptions (based on my tests) correct.

I've use a home brew of decreased viscosity epoxy for similar reasons and have stopped using "penetrating epoxies" all together.

As Michael said, you want 100% solids epoxy as your moisture vapor barrier, nothing less, which is where all "penetrating epoxies" (like CPES) fail. People think of it as a cure all for rot and other issues, it's not. Thinned epoxy is just part of a system that can stave off moisture ingress or partially return some structural integrality to damaged wood fibers.

No product that I've used can restore rotted wood to a useable material again. I've tested all the major brands and a few home mixtures and zip, nada, none are especially effective at turning wood mush into something useable.

Damaged wood cells have to be replaced, not coated. You can replace the damage with plastics or more wood.

For the transom holes mentioned, the best method (again it's a system thing) is to remove any bad wood, wet out with unthickened epoxy, that is warm (100 F to 120 F degrees), preferably with warm wood (again 100 F to 120 F), but is in the cooling down stage (so it doesn't "out gas"). Then mix up some thickened epoxy, using a structural filler material (micro fibers, silica, etc.) and fill the hole (which should be over size by at least 30% of the previous diameter). Let this cure good then drill for new fasteners. The result is a hole, filled with an inert material, that will not let moisture pass it into the transom.

Check the contents label for the epoxy you're using, it should have 100% solids, or very near so, when cured.

Frankly the selling point of penetrating epoxy is to suggest it "penetrates" better (which it does), therefore making a better seal. The simple fact is that the penetration aspect doesn't matter, just the resistance to passing moisture vapor does, which penetrating epoxies suck at. A 1/16" of an inch coating of straight laminating epoxy of 100% solids will out perform a 1/4" penetration using penetrating epoxy. The bottom line? The amount of penetration doesn't mater, just the ability to resist moisture vapor.

mystic vision

9th June 2008, 11:57 AM

Hi everyone,
We just bought a Milo Craft Mallard and are looking for any information that we can get about the boat annd or the company that built it. It is fully restored and am anxious to learn more about its heritage and any details about them. We are located in the Midwest just above where the states Illinois, Iowa, and Missouri meet. We are right on the Mississippi River so if anyone is in this area pleast get in contact.

PAR

10th June 2008, 04:24 AM

Well, I guess I should reply to this person as it's quite likely I'm as close as most of the forum members will ever get and I'm still a couple thousand miles away.

My data base doesn't include your builder, so I'm out of luck, but more information would be helpful, such as year, type of boat, etc.

Second this site, though not exclusively, services the folks "down under", many from Australia and New Zealand.

Closer to your home, there are several sites with the possibility of others with similar craft.

That said, some photos can be helpful, especially if it's already restored. Boat is always welcome and helpful when attempting an ID.

bjersey

14th June 2008, 12:43 AM

I own three Woodies and one has to go.

I am selling a 1960 18' Milo-Craft that was completely restored by Milo's son in 1995. I am the second owner and I have owned the boat for over 30 years and it has always been garage keep. The motor is a 1960 Evinrude 75HP, that was rebuilt several years ago and has about 5 hours of run time.

The 1995 Eagle Claw trailer is included; tires are in good shape and can be driven anywhere.

The boat will need a very of few coats of varnish and you will need to epoxy (West System) a few pieces of mahogany veneer to the bottom of the hull. I will include enough 4 ' x 6" veneer to complete the small project.

This is a great boat with a lot of room; always draws attention.

Bob Jersey 847-924-5308
[email protected]

Call or email for pics