sealing the tender

I'm at the stage where I'm going to seal the tender. I'm going to use Isoflex as I have plenty left over from the front wheels. Of those who have done it did you have any of the fittings attached or did you just mask off all of the holes? Will masking tape be sufficient to protect the holes ?

I stuck candle wax in the threads as it will just push out when needed. Then masked the outside so the lip of the holes would get covered as well.

Thank you Lynn, as always great advice!

I had the water feed for the injector in place on mine, but that's it.

ChriX wrote:I had the water feed for the injector in place on mine, but that's it.

On the 4" DCC you need to remove the water supply to the injector in order to fit the injector later in the build.

I fitted bolts into most of the holes to block them for those I could not I used blue tack and tape. This later was not very successful as the POR sealer still seeped into the threads.

Ian

I seem to recall reading somewhere or hearing from someone that Isoflex does not like being continually submerged as it is when the tender is full. It is not designed to be underwater, certainly when I have taken the top off my tender the isoflex looks like it has altered, discoloured somewhat and has pulled off, bearing in mind that I have the whole thing powder coated and have just used it to seal the corners etc.

I used Isoflex 8 years ago in the tender of my 4" single cylinder engine and it's still perfect. At the end of each season I drain it down & dry it out for a visual check, no problems to date. Some people have had problems where the Isoflex has been put around the internal nuts too thinly and rust has started or the inside has not been degreased enough for it to stick. I usually put 4 -5 coats on around the internal nuts so they effectively disappear under a thick layer of Isoflex (three coats everywhere else). Having said that I've used the petrol tank sealer on my RL bellytank as I was quite impressed with it & the Isoflex in the tender.

Conclusion: They are both excellent products if used liberally, only time will tell which one lasts the longest on my Crane engine.  

Sealed it all up today. I put the Isoflex on pretty thick, where the dummy inspection hatch is on the back and bottom you can barely see the bolts!

 

IanL wrote:
On the 4" DCC you need to remove the water supply to the injector in order to fit the injector later in the build.

Oh really? Damn, I was hoping to paint it all in place but now it sounds best if I don't - thanks for the pointer Ian.

I'm going to seal the tender with as much of the fittings attached as possible. The only problem is that some of the bolts are too short, is anyone else seeing this problem?

The bottom step can't be fitted as there are no threads for the nut to catch. The brass M5 bolts for the water injector are also too short only catching one or two threads. Not really an issue, a trip into B&Q will fix this but it's not ideal.

Hi Alan

On my tender the bolts for the bottom step and the water injector were short, I just replaced with some longer ones. I sealed the tender and then painted it prior to attaching any of the fittings, I then used the isoflex primer again and resealed the tender. I didn't think to block the threads with wax or anything and the bolts easily re-cut the threads. I suppose there are a few ways of doing it with pros and cons for each, I'm just making it up as I go along

Cheers

Simon