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Jan Williamson

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OK, I guess I need to stop being so lazy and get with the program. I just went to the Raka web page and looked at all the information they have. That page has a good instructional area telling all about Epoxy, and how it is used, mixed and all the good stuff.

I have tried to use the search feature of this forum, but with a one or two word search, there is so much to sift through just to get to the thread that tells one what they want to know. I do know that all of these subjects have been covered before and I feel very selfconcious asking the questions all over again.

I can see that as one begins a boat, they become like a kid with a new toy, and have lots of questions. I also see that you experienced guys have the patience of Job when it comes to handling us "kids" Thank you :!:

I do shudder at the cost of Epoxy Resin, but I can see where it is much the best way to go for the keel. Weldwood I think will work for the rest of the boat, but I do think I will coat the boat with liquid resin to waterproof as per the recommendation of Raxa.

Thanks guys... :)

Tomorrow the "Honey" set aside all the "do's" so we can go get the wood we need for the first step of construction, and thinks the trip to get the wood will be a fun outing. She is leaving for a couple of weeks, and we may even be 3D by the time she gets home.

"As the Glue Thickens" Another book title :?:

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Guest Anonymous

Epoxy is more user friendly in home built projects of laminated plywoods, and coating of glass, when working by yourself, also. The cure time, the recoating, after you become familiar with it, makes for less work of grinding, and sanding in the inital layup.

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At a bare minimum, I would use epoxy for the keel, and the exterier joints: Hull joining, deck joining, transom to deck, transom to hull bottom, transom to sides, deck to sides, hull bottom to sides, and hull bottom to keel.

The rest could easily be done with weldwood.

You will also want to use epoxy when glassing... if you glass.

However, I did a very un-scientific test: I put some weldwood on a couple 2x4s and clamped together for a week. Then I took the blocks and submerged them in water for a week. (put a couple large rocks on them). After 7 days, I checked them... they had come apart.

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In my experience, 'pot' time is a relative term. The larger the batch, the faster it will kick if contained. I usually mix it up and spread it all out as fast as possible. This eliminates the confined mass that will generate exess heat and cause it to kick faster.

Maybe 10-15 minutes in the mixing pot, while having it spread out will give you scads of time. :) coat the surfaces first with un-thickened epoxy, then apply the thickened.

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Slow hardener will give you 30-45 minutes most likely, maybe more. In larger areas, I use the slow hardener, but most generally, I mix the slow with the fast and get teh best of both worlds. I really like the Raka epoxy. :)

Key is to get it out of the mixing pot as quickly as possible, then you have more time to work it.

I hope this is making sense. :oops:

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I want to venture a comment here as I am wanting to test my learning.

It seems to me that using clamps is good as long as there is enough Epoxy left between the boards to form a good bond. As far as keeping thins straight, setting the whole thing on edge (supported) on saw horses should allow you to let the clamps stay (if they are really needed after the screws are put in). I do not think you will have trouble with the boards mis-shaping if they are on edge as that is their strong position.

Now I am waiting for other posts to verify :D

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The assembly of the keel using clamps was best accomplished for me by laying out a series of cut lengths of 2X4 crosswise under the keel assembly. It doesn't take that many clamps to hold it together while you get the first few screws installed. Then it is a simple matter to move the clamp and drill and put the screws inplace. I left the keel laying on the blocks to cure with some cans of paint on it to keep it laying flat.

Where the biggest issue might occur is with the keel not being flat if you don't use the lengths of 2X4 as spacer blocks under it. It can get skewed a little if you clamp one area and the lift the next area to place a clamp and so on.

I used clamps on my keel with the Weldwood resin laying it flat on the floor as above and it went very quickly with no issues of misalignment.

I used 4 clamps and several nails to quickly pin the sections inplace so they wouldn't slip/shift at all. I simply ran a drill bit down thru the layers and then pounded in a 10 penny nail. When I pulled the nails I drilled the screw holes in the same place and placed the screws. When I flipped it over and did the other side the alignment was perfect.

Regardless of how you do it, you are going to have some small gaps where the sections meet each other. These can be filled with thinned epoxy and sanded flush. Learn to make dams at the ends of open spaces to contain the thinned epoxy and you will save a lot of frustration and epoxy.

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Jan, I disagree with some of my collegues on a few minor points. I think we're making this too complicated for you with talk of clamps, etc. I don't know anyone who built their keel that way, although some might have. I don't think you need to use clamps when gluing up the keel. The screws are the clamps.

You want to do the lay up on the floor. To avoid gluing the keel to the floor, get a cheap plastic painter's tarp and lay it down first, as epoxy and Weldwood don't stick well to the plastic! Both do, however, stick very well to concrete, and getting a keel unstuck from a concrete floor can be a challenge! There's a story in there, but you can fill in the details.

To use clamps, and you would have to have the keel up off the floor, suspended between sawhorses etc. to make room for the clamps. I think that's much more likely to cause twisting of the keel than doing the layup on the floor. By the time you get what are nearly 3 1x12x14's glued together, they are pretty heavy, and the wood will try to sag between the sawhorses or blocks or whatever you're using to be able to get the clamp under the keel. Plus, a clamp only applies pressure where it is; you would need cauls to spread the clamping pressure across the keel, and a clamp every foot or so along its length. This is way too much trouble for what we are doing.

With the slow hardener, you have a bit of time to brush on the epoxy and then lay the next board on top. I always mixed small batches of no more than 3 or 4 ounces for most projects, but you'll get a feel for this quickly enough.

Beg, borrow or steal a drill motor so you have two. I had a cordless and a corded drill, so that's what I used. Get a pilot drill/counter sink combo at the hardware store that matches the screw size you're using, and use that in one drill, and a bit in the other for driving the screws.

Here's a step by step method that might work for you ... its what I did:

Start by first drilling a few pilot holes in what will be the "top" lamination when you're doing the glue up. Start a screw in each one of these. You only need a few. Have the points of the screws sticking out the bottom of the board 1/16 or 1/8". These should be at one end of the board.

Spread the glue, and lay the board on top. The screw points will help keep it aligned, but you do have to watch it. Epoxy is pretty slippery, and the boards may try to slide against each other. Drive your pilot screws home. Then, working from that end to the other, pilot drill and drive screws in along the length of the assembly, making sure you are still aligned at the other end. I did mine every 6" or so along bottom and top, and toward the wider parts of the keel, a couple in the center.

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When I did the keel for my Vacationer, I made a long table of sorts to glue it on. Four sawhorses about 4-5 feet apart, all the same hight. Four 2X6s', 10 feet long on edge on top of the horses, each two joined to make 20 foot long beds about 18" apart. On top of the 2X6's, I placed 2X2's about two feet long every 12-14 inches to form a lattace. I then leveled and true the whole works. This then is what I glued the keel upon. The gaps between the cross pcs left room for the 4" "C" clamps that I used. Had about 18 of my own and borrowed a bunch more. I glued, then clamped, and then screwed from each side using No-Code, Sq drive 1.5" screws from McFeelys. With the whole thing up off the floor it made for a very easy job. The stem was added at a later time just on the floor.

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Jan

As per Franks message - get two of those combination countersinking/drill bit

The first two I bought must have been made of plastic 'cause they broke after about 4 holes (I don't think it was my fault :( )

The next one I bought was great - lasted the bottom and deck and only broke when I dropped the drill :oops:

I'm lost without it - off to the shops I go!

Andrew

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I have the center rough cut for the stem to make, and I'll be ready to glue.

I can't get over the great help you guys are, every step of the way so far, for me. As I get more into the project, I gain a little more confidence. Having never worked with epoxy and weldwood glue though, and seeing the trouble some have had, it is so good to have all the opinions at hand. I like the pilot holes before you spread the glue on. The boards don't slide around when dry, then you just have to line up the holes (with the screw sticking through the top board). That seems like it would speed the final assembly. Do-able for a person by their self. I have two drills to do there separate jobs, so that's a good one. I bought a spendy, but good quality counter sinking collar that fits over a #6 bit, and secures with a set screw. , Does anyone have a drill that is not coated with dried glue?? :D Arnie I like the idea of working at waist height too, I did all my cutting and lofting on saw horses. Really saved my back and knees :) I think I will tackle this at home rather than wait till tues at the school. I am really anxious.

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Jan, and others,

I gotta chime in here too, so here goes:

About the pot time of epoxy:

A lot depends on temp and humidity, also how quickly you start to spread it out, and of course how much you make.

I do small amounts, about 1 oz on average, and spread them out, and mix more and spread it out, etc.

I found that the fast hardener from RAKA will go off very quick, especially if you spread it out slowly.

For example: at 100 F, you mix it for 1 minute, and let it sit in your cup. It will get too hot to hold in less than 5 minutes and solid as a rock in a total of about 10 minutes. But if you spread it out within a minute (after mixing), you can play with it (smooth it out) for about 10 minutes.

at 90 F, it doubles the time, and 80 F it is even better.

The slow stuff is considerably slower: at 100 F mixed for 1 minute, and left in the cup, it will get too hot to hold in about 25 minutes, solid in about 70 minutes, unable to stir in about 30 minutes.

But, if you spread it out within 5 minutes, you can work it for an additional 30 minutes or so. It is solid within a couple hours this way.

Needless to say, I use a lot of slow, and almost as much mixed, and very little of the fast alone. I do the fast when I have a small item to set and I need it to setup quickly.

As far as the keel goes, Frank is pretty much right on! At least pretty close to the way I did mine. I have about 5 5 gallon buckets of paint. So, I used them to "clamp" the parts of the keel together, while I screwed in the screws.

I would recommend that you find the flattest area you can, if you do it on the hump of a road, you will get a strangly shaped keel!

I used the slow mix and took my time to get things lined up, placed a couple of nails to keep the two pieces from sliding, placed the buckets, and started screwing in the screws.

For Thickener, I use two things, so far. I use some of the dust from sanding, and I used silica. I really like the silica, but I use the dust to "match" some areas, like filling in the screw holes. It is a little darker than the original area, but it looks better than the clear plug on top of the screw that you would get from silica.

I have heard other people using other things, and sometime I will probably try other fillers too.

I strongly recommend placing plastic or wax paper down before doing the keel... Mine stuck in the ONE spot where I did not put some wax paper. There is still a small chunk of keel stuck there! I filled my hole in the keel with more epoxy.

Have fun. I really like epoxy. I was planning on using weldwood, but the epoxy is so easy I use exclusively.

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Texas- thank you for the time table on the epoxy, it is good to know that I may have 2 hours or so. I need that much time :roll: . I am definately using the slow hardener, in the evening, on the garage floor. I may intially suspend the keel on 2x4s, to aid in clamping, but once it is all glued I'll use the "paint can idea on the floor. I think it is pretty flat. I am all done cutting everything out for the keel, so as soon as UPS gal delivers the epoxy (Raka) I'll be ready to glue. So while I am waiting, I will build the dolly :)

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