1988 Thompson 240 Fisherman -- Restoration Dabbling

Hey all,

I just bought a 1988 Thompson 240 Fisherman with an OCR 4.3L Inboard/Outboard. I'd like to restore her as much as I can, but will have to do it over the course of some time due to financial restrictions and the desire to get her on the water. My intent for this thread is to document what I'm working on and to seek out advice from the amazingly helpful people on these forums; I can't say how many awesome and helpful threads, by some astoundingly talented individuals, I've read and searched through. I'm truly taken aback by how gracious people are with their time and knowledge on this forum.

I plan on asking many questions, and it seems evident that I'll be receiving some really good advice. I'll try to consolidate all this in a type of FAQ format. I hope this will help future readers.

Please see a few images below. These are after a full day of scrubbing.

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling


The following are not necessarily frequently asked questions, but the questions/answers will be formatted as such. These are mostly questions I wondered about and either received answers for below, or found the answers to myself. The intent is for quick reference for anyone seeking answers to similar questions. I'll continue to develop this list as I work through my project.

Remember that many of these questions can be searched/googled with excellent results.

• Q: Should I use caulk or some other type of sealant on my boat?
  A: You should not use non-marine caulk. You should use marine grade sealant. Two typical varieties used include
  
  a. 3M 4200 Sealant for non-permanent seals (i.e. between parts you may at some future date need to access), and​
  b. 3M 5200 Sealant for more permanent seals.​
  
  Note that for sealing wood, other applications are more appropriate, such as enclosing the wood in fiberglass.
  
  
• Q: I have some corroded fasteners (bolts/screws) which I cannot remove because my screwdriver/wrench is destroying the head.
  A: Marine environments can often lead to corrosion, which seals surfaces of metal together, making fasteners difficult to remove. Further, the location where you would typically rotate the fastener may be compromised due to corrosion. These fasteners can sometimes be loosened by the following methods, or a combination thereof.
  
  a. Heating the fastener.​
  b. Applying a penetrating catalyst to the fastener (such as PB blaster) and allowing the catalyst to sit (say for up to 10 minutes).​
  c. Rather than using a screwdriver to turn the fastener, grab the head of the screw with some pliers.​
  d. Drill out the fastener with left handed drill bits. Reverse your drill to drill counter-clockwise; the bit is oriented so as to drill into the fastener in this direction (opposite normal drill bits). As you drill into the fastener, you are applying a counter-clockwise force onto it, which is the same as trying to loosen it with a screwdriver. With any luck, the fastener will come loose. Take care not too drill too far as you may damage the area behind the screw.
  ​

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Reserved 2.

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Andy82 said:

Reserved.

Click to expand...

Is that like setting up a folding chair in case a parade breaks out?

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

It appears that I'll have to take apart my outboard drive. The guy I bought the boat from said that on his last trip, they had a drive malfunction. The propeller was spinning, but wasn't providing any force to move the boat. He said the mechanic he took it to told him the Gimbal Bearing burned out.

I figure that when we remove the outboard drive, it will be a good opportunity to make sure the transom is well-sealed. I have a few questions that I couldn't readily find answers to, listed below.

• To ensure the best seal, would I use caulk?

• Is there a specific kind of caulk to use?

• Is there a specific kind of caulk to use around engine components as opposed to caulk used for general sealing (i.e. around windows)?

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

GWPSR: LoL. I certainly hope so!

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

First, welcome to the iBoats drydock! There is a tremendous amount of aggregate knowledge here. Some of it as a result of a few folks who hang out here that work or used to work for several of the major manufacturers, or their material suppliers. Others as a result of actual study. The remainder however is some of the most valuable of all -- people, just like you, who tried things and succeeded or failed, so that you can reap the benefit of their combined experience. (As well as contribute your own)

The most important thing to keep in mind is that materials for marine applications are often unique. Non-marine caulks and sealants have no place for below the waterline, and limited use above. You will see a lot of references here to 3M sealants 4200 and 5200 (fast cure and otherwise)

4200 is good for things that you need sealed water tight, but would like to be able to disassemble again someday for repair or maintenance. 5200 is good for things you hope never come apart.

For sealing the surfaces of wood, you will see as many methods here as there are boats. Read them all and note the application and the results.

Good luck!

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Well, one of my first priorities was to get the trailer lights working in case I need to transport the boat somewhere to store it, or work on it, or even -hopefully- get it on the water. Of course the screws are all rusted to hell. I'm going to try some PB blaster + vice grips on the screws. If that doesn't work, may need to try drilling them out. Worst case, I may just need to replace the lights and rewire them. I'd like to avoid that, but we'll see.

Also, here's some pictures to see what we're working with...



I also added some pictures to the first post to show some overall shots of the beast.

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

When I need to fix trailer lights I just buy a new kit, rip the old one off and install the new set wires and all,.....

I also run a ground wire down each side so I can ground strait to the tow rig,.....Always seems like the ground though a hitch and trailer is a problem with older stuff,...............

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

GWPSR: Thanks for the recommendations/explanations. Those are terrific. I looked up the specs on the products - the 4200 has a tensile strength of 300psi (hence the manageable to remove) and the 5200 has a tensile strength of 700psi (hence the more permanent).

Teamster: Looking at the cost of new lights, they're pretty reasonable. So ya, sounds like most likely I'll need to pick up some new lights. I'll let you know how it all works out.

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Welcome to iboats. Nice boat. Good luck:joyous:

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Andy82 said:

GWPSR: Thanks for the recommendations/explanations. Those are terrific. I looked up the specs on the products - the 4200 has a tensile strength of 300psi (hence the manageable to remove) and the 5200 has a tensile strength of 700psi (hence the more permanent).

Teamster: Looking at the cost of new lights, they're pretty reasonable. So ya, sounds like most likely I'll need to pick up some new lights. I'll let you know how it all works out.

Click to expand...

YW.

Harbor Freight has a set of the large rectangular lights in an LED submersible configuration for about $35 (look for the coupons, they go on sale regularly). That's what I bought for my trailer. I need to also pick up 3 more red LED markers for the rear and a number of amber for the sides due to the size of the trailer.

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

on the locked screws, try using an impact screwdriver! they work awesome on locked srews and usually dont mess up the heads!

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Lwarden: thanks! I watched some videos and looked at some tool sites. Looks like another great solution.

I had another question. I bought a pretty sizable tarp (20' x 30') to cover the boat and a good portion of the trailer. My plan is to cover it any time it's not in use or we aren't working on it. I can't help but wonder if this is as good of an idea as I originally thought. My concern is that I'll be trapping in moisture and humidity which may do more damage than the full time sun and occasional rain. Anybody have any thoughts on this?

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

As long as you keep the "Tent" vented it should not "Humidify" and cause moisture to be trapped underneath. This will only occur in an almost totally enclose environment. You might want to consider using some pvc and make a domed/arched support. Cost's would be under $50 for the PVC and you'll already have the tarp. 3 -4 of these should make a nice "Garage" for your boat.



10' section of 3/4" PVC for the top. Red pieces are 3/4" T's & 90? elbows, 5' sections for the legs. Instead of Couplers use T's and run 10' sections between each support to connect them together. Hope that all makes sense.

Here's what another iBoats member built...

Re: 1988 Thompson 240 Fisherman -- Restoration Dabbling

Hoping to get started on the engine repair work. I assumed it would be best to post for engine help in the appropriate forum, so I posted here.