Replacing the dorsal on your Hawk HOME Parts and Planes For Sale

The stock dorsal of the Hobie Hawk is made from ABS plastic. The replacements I sell are made from polycarbonate which is much stronger than the ABS plastic. The Hobie Hawk is unusual because it used 3 different plastics in the making of the fuselage. The primer that was used on the factory Hawks worked well on the polyethylene nose pod and the center fiberglass cone section. It didn't work so well on the dorsal. Many times I hear people say that the dorsal is cracked but many times it is just the primer/paint starting to crack and flake off.

Before you replace what could be a perfectly good dorsal, take a razor and scrape or chip the paint off and check to see that indeed your dorsal is cracked. If it is only cracked you can use some CA glue to fix small non structural cracks.

The break in the dorsal I will replace here is a bit more obvious - it was snapped clean off during shipping... and showed signs of previous re-glueing.

If your dorsal needs to be cut off, take your new dorsal and align it with the old one so you know exactly where to cut through the tail boom.

CLICK ON THE THUMBNAILS TO ENLARGE:

After removing the radio and push rods I clean out the tail of the fuse' boom. I use a large drill bit and BY HAND carve out the epoxy down to the original dorsal insert.

I shave down the inside until I can see the gaps between the 4 "fingers" of the old dorsal insert. I then use an exacto saw blade and CAREFULLY cut out the epoxy from the 4 gaps between the fingers.

Now I can get a small screwdriver into the gaps and hopefully you can pop out these 4 "fingers" pretty cleanly. This one cooperated beautifully.

Clean out the inside and even sand it a little to remove any old residue. Also, sand and square up the tail end of the fuse' boom.

If you have a brand new dosal you may need to assemble it and glue it together with CA glue. Here is the entire assembly: Right and left halves, bellcrank and the dorsal "wedge" that will be pressed in later to really secure the dorsal. NOTE: Be really careful not to get any CA glue on the bellcrank pivot area!

With the dorsal assembled, spot glue the dorsal "wedge" inside the dorsal on one of the fingers, about 1/8" from the end with a MICRO DROP of CA glue. This will temporarily hold it on the end of the "dorsal fingers" and make getting the wedge in place a WHOLE lot easier when the time comes.

Next I use a small zip tie to compress the dorsal fingers snug around the wedge. Mix up some slow set epoxy and coat the inside of the fuse boom, the dorsal wedge and the dorsal fingers. With the zip tie on you should be able to start the dorsal into the boom easily. Cut the zip tie and press the dorsal all the way on.

Place the fuse somewhere that it can rest without rolling over and insert the main wing rod. Take the main wing incidence pin and insert it into the main stab' hole. Now you will be able to sight down the fuse' and get the stab and wings parallel. Once you get it perfectly straight, put a alignment marks on the boom and dorsal.

Now you will need to insert a 3/8" to 1/2" dowel down through the back of the nose pod to the end of the fuse'. When it stops it will be resting on the dorsal wedge. Take the fuse off the bench and back up the dorsal on a hard foam block on the floor. Now you will need to tap the dowel with sufficient force to break it free and wedge it into the dorsal. You can use a flashlight to shine through the dorsal and see that the wedge is seated properly.

Now that you have made sure everything is in place RE-CHECK the ALIGNMENT. With the exception of waiting for the epoxy to cure and re-painting, you are done!

Home

	After removing the radio and push rods I clean out the tail of the fuse' boom. I use a large drill bit and BY HAND carve out the epoxy down to the original dorsal insert.
	I shave down the inside until I can see the gaps between the 4 "fingers" of the old dorsal insert. I then use an exacto saw blade and CAREFULLY cut out the epoxy from the 4 gaps between the fingers.
	Now I can get a small screwdriver into the gaps and hopefully you can pop out these 4 "fingers" pretty cleanly. This one cooperated beautifully.
	Clean out the inside and even sand it a little to remove any old residue. Also, sand and square up the tail end of the fuse' boom.
	If you have a brand new dosal you may need to assemble it and glue it together with CA glue. Here is the entire assembly: Right and left halves, bellcrank and the dorsal "wedge" that will be pressed in later to really secure the dorsal. NOTE: Be really careful not to get any CA glue on the bellcrank pivot area!
	With the dorsal assembled, spot glue the dorsal "wedge" inside the dorsal on one of the fingers, about 1/8" from the end with a MICRO DROP of CA glue. This will temporarily hold it on the end of the "dorsal fingers" and make getting the wedge in place a WHOLE lot easier when the time comes.
	Next I use a small zip tie to compress the dorsal fingers snug around the wedge. Mix up some slow set epoxy and coat the inside of the fuse boom, the dorsal wedge and the dorsal fingers. With the zip tie on you should be able to start the dorsal into the boom easily. Cut the zip tie and press the dorsal all the way on.
	Place the fuse somewhere that it can rest without rolling over and insert the main wing rod. Take the main wing incidence pin and insert it into the main stab' hole. Now you will be able to sight down the fuse' and get the stab and wings parallel. Once you get it perfectly straight, put a alignment marks on the boom and dorsal.
	Now you will need to insert a 3/8" to 1/2" dowel down through the back of the nose pod to the end of the fuse'. When it stops it will be resting on the dorsal wedge. Take the fuse off the bench and back up the dorsal on a hard foam block on the floor. Now you will need to tap the dowel with sufficient force to break it free and wedge it into the dorsal. You can use a flashlight to shine through the dorsal and see that the wedge is seated properly.