Thin water

I am a beginner still and want to retire from the cops and robbers game in six years and just make boats (I am on the cops side of the game). I made a mold from scratch and the layup is now in the mold. I think this is the address to the thread http://www.modelpowerboat.com/forum/...read.php?t=186.

It will be a 72" deep V and should be able to take some heavy water when done. I have made some parts for Carl of plumkrazyrcboats.com and this will be a gift for him. He will set it up and get it on the water.

JIM





[Edited. Bad link and not directly to the thread.]

martno1fan

Is that Dougs deep v offshore hull youv,e made?,looks nice but a little narrow in the beam for its length i find what do you think?.

Justaddwata

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I am confused - "For all who want to make their own mold.." but your showing us a hull. Are there more pics or something?

Thin water

Justaddwata, the link is for the thread where the mold was made, from the plug to the picture shown. It is fairly long so transferring it was not a good idea. I should have the boat out of the mold this weekend and use it's final size to make the plug for the top mold.

With the thread another beginner such as myself should be able to start with their own plug and end up with a useable mold. I have been building parts in fiberglass for about two years now and just started making molds a few months ago.

The plug



The plug with flange being glued on



BIG mistake, I should have used surfacing primer instead of the paint shown. I was told the surfacing primer is a standard plug finish, well sanded and waxed. the paint stuck in the mold and ruined the plug.

Thin water

Here is the fiberglass laid up on the plug. Several layers of mat and coremat. Use no woven or the pattern will print through.

Thin water

Here is the layup with one layer of 1 1/2 oz mat, one layer of 3/4 oz mat and some tight weave cloth about to be wetted out and rolled with the roller at the transom.

Yes, it is Dougs offshore deep V. He has been following the mold making thread as I went. I think the design will be good, his plans are great.

JIM

Thin water

We have a boat! It was a little hard to get it out but no damage to the mold or boat. The layup seems perfect, nice and strong but light.

JIM

martno1fan

looks good so far yes doug designs a nice boat i built one of his 48" monos from wood and although i changed it a lot above the waterline i cant complain at all about the basic design.it runs very very well indeed .

Paul M

Very interesting thread, Jim. I will be doing a drag hydro soon. I am in process of making a one off for testing which will be made into a plug if testing goes well.

What spray gun did you buy for gel coat and where did you get it?

I don't want to buy junk but am looking to keep costs as reasonable as possible.

So your lay up was 1 layer 1.5 oz mat,,,1 layer of 3/4 oz mat and some cloth? What weight cloth? Any other details especially about problems and solutions you had, I would love to see.

I am getting tired of paying hundreds of dollars for low quality glass work....might as well do it myself

Thin water

The spray gun is known as a "Dump gun" Do not try to spray gel coat with a paint gun. It will fail and you will throw the gun away. If you manage to thin the gel coat enough to get it through a paint gun you ruined the gel coat. These guns sell for about $145 up to $200 on the net. Search for a ES G100 Gelcoat spray gun. Have plenty of acetone ready to clean the gel gun with. It must be "Ready, not in the can. Pour it in a bucket so the gun can go right in after removing the throw away pot. Move fast. You can add a small amount of acetone to your gel coat to slow down it's kicking off (about 2 tbl spoons to the pint) but if you spray in more than one heavy layer of the gel coat it will lift the first layers and "Gator". Styrene can also be used to thin the gel and is the recomended stuff to use.

Here is a picture of one



The biggest problem is I painted the plug instead of finishing it in gel coat or polyester based primer. Paint will stick when you make the mold. I may have not waxed it enough either. The plug was broken into hundreds of peices to get it out but that is OK since the mold is good.

Fill any tight corners with thickened resin before laying up your mold so it won't get air bubbles trapped between the glass and gel coat.

I don't know the weight of the cloth. It was given to me. It has a very fine tight weave but is a pain to get bubbles out of.

See the entire thread from the link in the original post for the most info.


JIM

Paul M

Have you ever done epoxy/carbon boats in your polyester molds? Seems someone told me once that you can mold epoxy in polyester molds but not the other way around due to the high temps poly creates.

Paul M

http://cgi.ebay.com/ebaymotors/Gelco...spagenameZWD1V

Is this the one you have? Do you like it?

MrMikeG

I have a "dump gun and the nozzle is removable so you just put the nozzle in acetone to clean, the rest isn't touched by the Gel-coat. Much easier. Before that I used a paint gun with an extra large nozzle, worked good but took a lot of maintance.

Thin water

I should have been clearer, I just throw the nozzle and the part it screws into into the acetone. The rest of the gun can just be wiped off.

You will never over heat a mold with poly making an RC boat. It is not nearly thick enough to build up much heat. When making a real boat you can ruin any mold if you lay it up to thick with poly or epoxy because they both make a lot of heat when laid on thick all at once.

The ebay link is the same gun I have, it works well.

venomxx

You can just use a brush and brush it over, do it about 2 thick layers and you're good. Spray guns are messy to clean up.

Tried vacuum bagging?

MrMikeG

Venomxx if your spray gun is "messy" your using the wrong one. A dump gun only has one part to clean and it takes seconds

Paul M

I have tried using a brush. No offense, but talk about a mess[:@] I would think a gun would be alot faster and more even. I would like to use epoxy (west system). I know its a good bit more than polyester, but the smell is not so bad.

Is there such a thing as epoxy gel coats or do you just mix in pigment and a little colloidal fibers til it's about like ketchup? Or I suppose you could do what Venom was talking about and spray 2 coats of resin, but would that be thick enough?


RE: vacuum bagging? That's the plan


Thin water - sorry for encroaching upon your thread, but you seemed pretty open to questions and i appreciate the info.

Justaddwata

My Feedback: (3)

Well I gotta say that after waiting a few months to have a guy help with an apache mold I have that I decided to give it a shot on my own. I did plenty of reading up (this being my first mold work and all) and thus far all I can say is you guys can keep it [:'(] Talk about your hard work. I figured it would be a little challenging but man was I off. Just prepping the mold and I was tired. Had to strip it of overspray first (no easy task), 3 coats of wax and then release agent. Then I am told 5 coats of wax and then PVA. I figured that the agent I used and 3 good waxings would have done it - dont have my answer yet [X(]

DId the brush trick for gel coating. Tried to get it done in one coat - never going to happen. Two coats and twice as much gelcoat as I probably needed. Spraying (even with clean up) has to give a better result and much less effort.

Then whipping out 17ft of 10oz cloth - just for the hull (two layers for the 84" hull). An hour fitting it into place. Then resin time. I think I have a few dozen more gray hairs from working that resin. No easy task and fighting the cloth and airbubbles the whole way.

The cloth finally yeilded to my patience and found a comfortable home among the resin with in a few minutes of the resin deciding it was time to kick.

And I gotta say one word of advice - DONT BUILD BOATS IN YOUR BASEMENT My house smells like a boat yard and the misses is not too pleased with me (another dozen gray hairs from that too). Plus I have had a headache for two days (not sure if that is the resin or the misses causing that)

Many thanks for the inspiration to have a go at it but I am thinking I might continue to pressure my buddy to do some of this grunt work. I am more happy drilling holes in glass than manipulating it.

I have not yet pulled the hull from the mold (if it will let go) and no glass on the deck or hatch yet but here are some pics of where I came undone

Thin water

Youe stuff loks good Justaddwata. It will be worth it in the end. A lot of people think that twnety bucks worth or resin and ten bucks worth of glass should not cost them much once it is made into a boat. All the time spent is what costs the big bucks. Youe layup looks very good, getting the bubbles out is the most important thing.

Post pictures of the build. I did a posting of how to glass in stringers on modelpowerboat.com that came out fairly good.

Good luck with your boat.

JIM

Justaddwata

My Feedback: (3)

Thanks Jim - I wish it were just $30 in materials. Think I am at $300 + the mold (Should have some left over after this hull though). I glassed the hatch and deck late last night - less fun than the hull. I think I will have to do at least one more boat before handing it back to a professional. Figure I have learned a few things already that may make the next one easier (an exhaust fan being one of them)
Theres a gallon of resin ($48), half a gallon of Gelcoat ($30), and around 140 sq ft of 10 oz cloth in this one so far.

glennb2006

You could always sell some of those amazing amount of props on the board in picture three ora couple of engines to finance it all!!

Looks good, be interesting to see it progress to a completed boat.

You think that's fun, wait until you are fighting with fibreglass cloth and resin to get the deck bonded on to the hull at the bow end. Unless, of course, your arms are five feet long.

Have fun,

Glenn

Justaddwata

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For some reason I can only buy props - never sell them (one of those addictions I have [])

Thankfully the deck and hull are a shoe box fit (deck overhangs the hull) so the seam should be a lot easier than most (though not very inconspicuous). I could probably find a way to blend it but think that I have to tackle this one one step at a time.

Paul M

I'm impressed Matt. The pics do not show that you struggled and 10 oz cloth is not easy to tame. Had you considered going lower weight cloth with an additional layer or 2? When do you plan to pop out the hull?

MrMikeG

New mold? I think you will be doing some more sanding too! Tape the seam, even shoe box seams. [8D]

Justaddwata

My Feedback: (3)

Had I known the 10oz cloth was this stiff I might have looked at 7oz and done 3 layers or 6oz x 4. I will have a look at pulling the hull this afternoon. The smell in the house is down to an acceptable level so it is time to do some more glass work

It is a preloved mold that I got from Offshore Marine/ Eddy B. I am thinking that upside down will be easier to do the taping inside the hull. That and a long stick