Jump to content
Sign in to follow this  
Bill H

Unconventional pump boat part VIII

Recommended Posts

Bill H

My paint and epoxy supplier finally came through with products so we can finish the boat now. A long and frustrating wait it has been too.

 

My experience with the local boats has been they tend to fail either because the marine borers eat through the log bottom, or the cheap plywood most builders use delaminates and rots or the wood frame succumbs to dry rot and fails. I addressed each of these issues with this boat.

 

First, I substituted plywood for the traditional log keel (plywood being less susceptible to marine borers. I used the highest quality marine plywood I could find here and verified it's quality by subjecting it to a 48 hour boil test. Lastly, I am using a high tech and thorough painting system for the entire boat as follows: All bare wood is first treated with clear epoxy. That is covered with epoxy primer, that is covered with at least two coats of epoxy top coat. Underwater areas are also coated with epoxy anti-fouling paint. I'm confident this boat will out live the local versions by many years because of the above steps. Of course, epoxy paints and clear epoxy are not inexpensive (average about 1,500p per gallon) but a few extra pesos spent on coatings will at least triple the lifespan of the boat so I think it's money well spent.

 

After filling all screws and joints with marine epoxy putty, we coated the entire hull with the clear laminating epoxy that we'd used to epoxy the plywood sheets together. When it began to reach the end of the tack stage, we begin applying the epoxy primer paint coat. Unfortunately, all the supplier could give me was battle ship gray epoxy primer, but with the first application of the top coat, the color will change.

 

The first picture is of the hull being coated with clear laminating epoxy. The second picture shows the hull after the epoxy has been applied as we begin to apply the epoxy primer paint.

post-8579-0-16145600-1331025173_thumb.jpg

post-8579-0-80518400-1331025695_thumb.jpg

Share this post


Link to post
Share on other sites
Bill H

The final two pictures show the epoxy primer being applied to the bow and the hull once all the primer has been applied.

 

Bill

post-8579-0-75933900-1331025900_thumb.jpg

post-8579-0-79671000-1331025926_thumb.jpg

Share this post


Link to post
Share on other sites
Topper

It sounds like you'll have one "hell of a fine boat" when you are finished. Thanks for keeping us posted on its development. I can hardly wait to see it in the water.

Share this post


Link to post
Share on other sites
samatm

coool . I am curious how you perform the 48 hour boil test on the marine ply.

Also have you calculate how much weight you have added. Have you taken any special preventive precaution with the outrigger struts?

Share this post


Link to post
Share on other sites
easy44

coool . I am curious how you perform the 48 hour boil test on the marine ply.

 

 

Hmmm...maybe put a piece in water and boil for 48 hours?

  • Like 1

Share this post


Link to post
Share on other sites
Bill H

coool . I am curious how you perform the 48 hour boil test on the marine ply.

Also have you calculate how much weight you have added. Have you taken any special preventive precaution with the outrigger struts?

 

Hmmm...maybe put a piece in water and boil for 48 hours?

 

Well, yes that's pretty much what you do. I pulled the samples out (2 samples) to check for delamination every few hours. I photographed everything as the test progressed. I also kept a lid on the pot to minimize water loss and added water as needed. I'd done an earlier test on some marine plywood I purchased at my local lumber yard and it failed in less than 2 hours and was completely delaminated in 3 hours.

 

Some people scoff at this because unless you sail near volcanoes you won't put your boat in boiling water. However the purpose of the boiling water is to act as a time accelerator. You could soak the samples in water for months or you can boil them for hours, the end result is the same. Quality marine plywood will not delaminate in a 48 or even 72 hour boil test. As noted, the local cheap stuff failed in two hours and was completely delaminated in 3, that's pretty bad. It explains why local boats don't hold up very well too! Granted my quality plywood costs about 30% more, but then it won't fail in a couple of years, so that 30% is money well spent in my view.

 

To answer the other question: Yes, the bamboo gets the same coating treatment as the hull did. The bamboo that will be in the water all the time also gets anti-fouling paint on the portion which will be in the water.

 

I have calculated weights on the boat. I have used those to calculate the anticipated water line. We'll see how good my math is when we put the boat in the water. Fingers crossed on that one.

 

The calculated weights on the framing wood is 152# and the plywood 250#. Total boat weight is 402# calculated. The epoxy and paint on the boat has added about 25#. That's a little hard to calculate because there is some evaporation loss to the solvents in the paints and epoxies. In any case, it's such a small number as to be inconsequential.

 

My build crew is very proud of this boat. They told me today this is a 25 year boat for sure. Boats that live in the water here are doing good to make it 5 years. 8 if they are hauled out most of the time. So, clearly my crew has a pretty good opinion of this boat.

Edited by Bill H
  • Like 1

Share this post


Link to post
Share on other sites
shielaerin

Hi, are you selling pumpboats? I have a friend want to buy a pumpbaot for private use only...if you know anyone please let us know. Thanks.

Share this post


Link to post
Share on other sites
Bill H

Hi, are you selling pumpboats? I have a friend want to buy a pumpbaot for private use only...if you know anyone please let us know. Thanks.

 

Yup we can do that too. PM me. Let me know how large you're looking for and how much horsepower you think you need.

Share this post


Link to post
Share on other sites
Stranded Shipscook

Sadly a lot of Marine Ply is a "fraud" here. I have a close find of mine who buildhis huge sailing catamaran in 79 here, at that time he found one supplier who had good plywood. The Rest he already imported back then from all over the world.

 

The supplier isn't there anymore,and he hasnot found another,so he brings the boards for repairs and maintenenace with him from Malaysia or other places in the region (alsolighter, crucial on a sail multihull), but he does the repairs here in Tambobo/Negros every year..

 

Yup,every year, thats what a boat requires... annual repairs. Just info for the guys who dreamof having a boat, i have been there,done that, got the video, lol.

The boat sailed around the world and still sails extensively btw.,so its possible, he can't imagine that it will ever die in his lifetime actually. So your 25 year prediction is even lower than it could be.

 

My Sailing catamaran ( build in Germany though )doesn't have a "lifetime" really. Once the wood is fully "Epoxied",it is a new materialwhich can endure huge loads and lifetimes.

 

 

The California Windfarm wings are made of this too. Also wings or better, entire SailAirplanes, and the once one seeflying around in Germany are often build in the 50ties/60ties by "amateurs".

 

fazit is,if one puts enough love into details, boats can last a lifetime and longer.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

  • Commercial Banner Advertisers

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use, Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue..