Coffin box build

Building a coffin box for a customer.  Using a temporary/rough mold to make both outside and the inside liner.  

Here is a link to the google gallery which will be updated with a lot more pictures....

All the materials used in this project are sold through our store...... gulfstreamcomposites.com

https://goo.gl/photos/Yh86i9b7s4t74ezG6

first layer of glass in the mold, one more layer to go, the the inside liner gets built and dropped in





Used PVA as the mold release on the molds. PVA is sold here.... link to PVA

male mold for liner, glassed, then core material glued up.  Then laid it in the female mold with epoxy putty.

The epoxy being used is Raka epoxy....

http://www.gulfstreamcomposites.com/category-s/129.htm

Using a combination of 1708 and 10 oz woven for the glass skins....

link to 1708

link to 10 oz woven cloth

progress on the coffin box build.  After epoxy gluing in the liner (with the core material in place) the space is filled with expanding foam.  Molds pulled apart, and the box trimmed to shape.  Next the bottom of the box get glassed in, then fairing and finishing

a lot more pictures here

https://goo.gl/photos/Yh86i9b7s4t74ezG6

started fairing, very happy with the overall fairness.  The lid and the lip of the box were both covered with a couple layers of glass.  



this is actually the bottom of the box....

I forgot to show how I made the bottom....  started with glass on a flat surface, epoxied down the core, made a drain recess, glassed the topside.  The glass on the mold surface is like a flange to glue down onto the box, excess epoxy squeezes out (clean it up while its wet ).  Trim the outside flush.  I used the grinder to make a grove in the foam all the way around the box on both the inside and outside skin/joint, so that when the bottom was pressed down it makes a nice inside fillet of epoxy putty to ensure a good bond between the two parts.  

fillet and glue putty is our fillet/glue blend....

http://www.gulfstreamcomposites.com/product-p/lhm_filletblend_8oz.htm

core material is plascore honeycomb, found here...

http://www.gulfstreamcomposites.com/category-s/137.htm





dry fit



bottom of box glued down, you can see the putty through the glass (brown)

That is slick. What did you do, cut the lid off the molded piece? Any issue with the foam deforming the outer or inner skins?

daytrip wrote:What did you do, cut the lid off the molded piece? Any issue with the foam deforming the outer or inner skins?

Yes, the top was molded into the bottom of the molds, and I just cut it off. The skins were braced pretty well, 3/4" malamine and MDF with 2x4 around the outside and 2x4 bracing on the inside liner, no deformation at all.

after sanding the first fairing pass





second fairing pass today, if I have time tomorrow I will hit it with primer to see where it stands.

Looks good. What are you going to do to seal the top to the box when closed?

DAYTRIP wrote:Looks good. What are you going to do to seal the top to the box when closed?

A gasket on the lid, picked it up yesterday along with the hinges and drain plug.

rolled some prime on yesterday, using the EMC high build epoxy primer.....

http://www.gulfstreamcomposites.com/EMCprimers-s/126.htm





at least one more application of fairing, then several more coats of primer. Will be cutting hole for drain and holes for mounting bolts next.

Looks great. What are the dimensions ?

DAYTRIP wrote:Looks great. What are the dimensions ?

24 tall, 22"x48" it's the dimensions needed to fit on the front hatch of customers boat. It's a contender 27, not sure what year/model

Easy to build using 4x8 materials

more primer, more fairing.  PVC epoxied into the bottom for the mounting bolts.











using the same hinges I used on the last coffin box, super heavy duty and rounded



Using EMC highbuild primer, it sure fills and builds fast !

link to the primer: http://www.gulfstreamcomposites.com/EMCprimers-s/126.htm

locating the hinges. Drilling holes to a little over 2x fastener diameter. I then use a screw locked into the drill chuck to route out the foam around the inside of the fiberglass skin. Last step is to pour the hole with epoxy. No way these hinges can pull loose

Another coat of EMC highbuild primer, then today the first two coats of Matterhorn White on the inside of the box. Picture shows only the first coat. Second coat gave full coverage. The guide coat is just some spray paint, it lets you see where you need to sand and keeps you (hopefully) from sanding through. Actually, I did sand through in some spots on the inside, but the paint covered just fine. Paint is rolled on (no tipping) with a cigar style roller. I used no reducer and it laid out like glass.

sanded outside of box to 220 grit.  Used my neighbors spray booth just to keep dust off, rolled a couple coats of EMC Quantum paint on in the booth.  Used about 1/2 quart so far and covered about 56 square feet with two coats.    I need to put a coat on the boattom of the box, and I may put another coat on the inside of the box, but besides that I think the painting is done.  The guy I am building this for wanted a non-skid pattern on the top, so that will happen next week after I install the hardware and gasket



this picture was taken right after rolling the paint on, it is in the process of laying out.



This is after about 1 hour, all tightened up and dry to the touch.

Very nice!

thanks Larry ! The customer I am building this for is a guide in Key West, so just to make sure it gets install correctly I think I will need to go on a fishing trip

ready for hardware....

finished up. Hardware mounted and a non-skid (kiwigrip) pattern on the lid.

Delivered the coffin box last week to Key West. The color was a good match. Bolted the box to the forward hatch, then we went fishing

Box looks great! Where's the fish?

Cracker Larry wrote:Box looks great! Where's the fish?

Haha, well I guess the fishing can be slow sometimes no matter where you are. We only got one tuna and got sharked